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Sound Really Can Travel in a Vacuum, And We Can Finally Explain How

August 16, 2023 by admin 0 Comments

Given the right circumstances, it is possible for sound to travel through a perfect vacuum. Now two physicists have worked out what those conditions need to be.

Zhuoran Geng and Ilari Maasilta of the University of Jyväskylä in Finland say their findings represent the first rigorous proof of complete acoustic tunneling in a vacuum.

To achieve it, you’ll need two piezoelectric materials, which are capable of turning movements into voltages (and vice versa). The objects need to be separated by a gap that’s smaller than the wavelength of the sound you want to send, which will then completely jump – or ‘tunnel’ – across that space.

We’ve known about acoustic wave tunneling since the 1960s , but scientists have only begun to investigate the phenomenon relatively recently, which means we don’t yet have a very good understanding of how it works.

Geng and Maasilta have been working on fixing that, first by describing a formalism for the study of acoustic tunneling, and now by applying it.

In order to propagate, sound requires a medium to travel through. Sound is generated by vibrations, which causes atoms and molecules in the medium to vibrate; that vibration is passed on to adjacent particles . We sense these vibrations via a sensitive membrane in our ears.

A perfect vacuum is a complete absence of a medium. Since there are no particles to vibrate, sound shouldn’t be able to propagate.

But there are loopholes. What qualifies as a vacuum can still buzz with electrical fields, which makes piezoelectric crystals an intriguing material for the study of sound across otherwise empty spaces.

These are materials that convert mechanical energy into electrical energy , and vice versa. In other words, if you place a mechanical stress on the crystal, it will produce an electric field. And if you expose the crystal to an electrical field, the crystal will deform. That’s known as the inverse piezoelectric effect .

OK this is where it gets fun. A sound vibration exerts mechanical stress. Using zinc oxide as their piezoelectric crystals, Geng and Maasilta found that a crystal can convert this stress into an electrical field if certain conditions are met.

If there is a second crystal within range of the first, it can convert the electrical energy back into mechanical energy – et voila, the sound wave has traversed the vacuum. In order to do this, the two crystals have to be separated by a gap no wider than the length of the initial acoustic wave.

And the effect scales with frequency. As long as the vacuum gap is scaled accordingly, even ultrasound and hypersound frequencies can tunnel through the vacuum between the two crystals.

Because the phenomenon is analogous to the quantum mechanical effect of tunneling , the results of the research could help scientists study quantum information science, as well as other areas of physics.

“In most cases the effect is small, but we also found situations where the full energy of the wave jumps across the vacuum with 100 percent efficiency, without any reflections,” Maasilta says .

“As such, the phenomenon could find applications in microelectromechanical components (MEMS, smartphone technology) and in the control of heat.”

The research has been published in Communications Physics .

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Science Struck

How Does Sound Travel? Here’s the Science Behind This Concept

When sound waves travel through a medium, the particles of the medium vibrate. Vibrations reach the ear and then the brain which senses them and we recognize sound. Read on for an explanation of how sound travels.

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Sound is a series of compression and rarefraction waves that can travel long distances. It is produced by the vibration of the particles present in its medium; a medium is the material through which sound can travel. Presence of a medium is a must for the movement of sound waves. There are various types of medium through which sound waves can move like solids, liquids, gases, plasma, etc. Sound cannot travel through vacuum.

Characteristics of Sound Waves

The speed and the physical characteristics of sound largely varies with the change in its ambient conditions. The speed of sound depends on the density of the medium though which it is traveling. If its density is quite high, then sound would travel at a faster pace. When sound travels through gaseous medium, its speed varies with respect to changes in temperature.

The frequency of sound waves is nothing but the total number of vibrations that have been produced. The length of sound waves vary according to its frequency. Sound waves with long wavelengths have low frequency or low pitch; and those with short wavelengths have high frequency or high pitch. Our ears are capable of hearing only those sound waves which lie in the range between 20 and 20,000 vibrations per second.

How do Sound Waves Travel?

Basically, there are three things that are required for the transmission of sound. They are: a source that can transmit the sound, a medium through which sound can pass (like, water, air, etc.), and the receiver or the detector which receives the sound. The traveling process of sound has been explained below.

Creation of Sound

When a physical object moves in air, it causes vibrations which leads to formation of a series of compression waves in the air. These waves travel in the form of sound. For instance, when we strum the strings of a guitar or hit the head of a drum, the to-and-fro motion of the strings or the drum head creates compression waves of sound in the surrounding air. Similarly, when we speak, our vocal cords vibrate and the sound is created. This type of vibration occurs not just in atmospheric air but in other mediums like, solids and liquids as well. For instance, when a train is moving on a railroad made up of steel, the sound waves thus produced travel via these tracks.

At room temperature, sound travels through air with a speed of 343 m/s, through water at 1,482 m/s, and through steel at 5,960 m/s. As you can see, sound waves travel in a gaseous medium at a slow pace because its molecules are loosely bound and have to cover a long distance to collide with another molecule. In solid medium, the atoms are so closely packed that the vibration is readily transmitted to the neighboring atoms, and sound travels quite fast. In liquid medium, the bonding between the component particles are not as strong as in solids. Therefore, the sound waves move through it at a less speed as compared to solid.

Detection of Sound

When the sound waves hit the receiver, it causes some vibration in that object. The detector captures just a part of the energy from the moving sound wave. This energy of vibration is then converted to electrical signals. Thus, when the sound waves reach our ears, the eardrum present inside it vibrates. This vibration reaches our inner ear and is converted into nerve signals. As a result, we can hear the sound. Devices like microphone can detect sound. The sound waves create vibrations in its membrane which forms electrical signals that gets amplified and recorded.

So, how does sound travel? Vibration of an object causes vibrations of the same frequency in the surrounding medium. The vibrations are sent to the inner ear. After the auditory nerve picks up these vibrations, electrical signals are sent to the brain where the vibrations are recognized as sound.

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Traveling waves

17 How sound moves

Speed of sound.

There’s a delay between when a sound is created and when it is heard. In everyday life, the delay is usually too short to notice. However, the delay can be noticeable if the distance between source and detector is large enough. You see lightning before you hear the thunder. If you’ve sat in the outfield seats in a baseball stadium, you’ve experienced the delay between seeing the player hit the ball and the sound of the “whack.” Life experiences tell us that sound travels fast, but not nearly as fast as light does. Careful experiments confirm this idea.

The speed of sound in air is roughly 340 m/s. The actual value depends somewhat on the temperature and humidity. In everyday terms, sound travels about the length of three and a half foot ball fields every second- about 50% faster than a Boeing 747 (roughly 250 m/s). This may seem fast, but it’s tiny compared to light, which travels roughly a million times faster than sound (roughly 300,000,000 m/s).

Sound requires some material in which to propagate (i.e. travel). This material sound travels through is called the medium . You can show that sound requires a medium by putting a cell phone inside a glass jar connected to a vacuum pump. As the air is removed from the jar, the cell phone’s ringer gets quieter and quieter. A youTube video (2:05 min) produced by the UNSW PhysClips project shows the demo with a drumming toy monkey [1] instead of a cell phone.

What affects the speed of sound?

Sound travels at different speeds though different materials. The physical properties of the medium are the only factors that affect the speed of sound- nothing else matters.

The speed of sound in a material is determined mainly by two properties- the stiffness of the material and the density of the material. Sound travels fastest through materials that are stiff and light. In general, sound travels fastest through solids, slower through liquids and slowest through gasses. (See the table on this page). This may seem backwards- after all, metals are quite dense. However, the high density of metals is more than offset by far greater stiffness (compared to liquids and solids).

The speed of sound in air depends mainly on temperature. The speed of sound is 331 m/s in dry air at 0 o Celsius and increases slightly with temperature- about 0.6 m/s for every 1 o Celsius for temperatures commonly found on Earth. Though speed of sound in air also depends on humidity, the effect is tiny- sound travels only about 1 m/s faster in air with 100% humidity air at 20 o C than it does in completely dry air at the same temperature.

Nothing else matters

The properties of the medium are the only factors that affect the speed of sound- nothing else matters.

Frequency of the sound does not matter- high frequency sounds travel at the same speed as low frequency sounds. If you’ve ever listened to music, you’ve witnessed this-  the low notes and the high notes that were made simultaneously reach you simultaneously, even if you are far from the stage. If you’ve heard someone shout from across a field, you’ve noticed that the entire shout sound (which contains many different frequencies at once) reaches you at the same time. If different frequencies traveled at different rates, some frequencies would arrive before others.

The amplitude of the sound does not matter- loud sounds and quiet ones travel at the same speed. Whisper or yell- it doesn’t matter. The sound still takes the same amount of time to reach the listener.  You’ve probably heard that you can figure out how far away the lightning by counting the seconds between when you see lightning and hear thunder. If the speed of sound depended on loudness, this rule of thumb would have to account for loudness- yet there is nothing in the rule about loud vs. quiet thunder. The rule of thumb works the same for all thunder- regardless of loudness . That’s because the speed of sound doesn’t depend on amplitude.

Stop to thinks

• Which takes longer to cross a football field: the sound of a high pitched chirp emitted by a fruit bat or the (relatively) low pitched sound emitted by a trumpet?
• Which sound takes longer to travel 100 meters: the sound of a snapping twig in the forest or the sound of a gunshot?
• Which takes longer to travel the distance of a football field: the low pitched sound of a whale or the somewhat higher pitched sound of a human being?

Constant speed

Sound travels at a constant speed. Sound does not speed up or slow down as it travels (unless the properties of the material the sound is going through changes). I know what you’re thinking- how is that possible? Sounds die out as they travel, right? True. That means sounds must slow down and come to a stop, right? Wrong. As sound travels, its amplitude decreases- but that’s not the same thing as slowing down. Sound (in air) covers roughly 340 meters each and every second, even as its amplitude shrinks. Eventually, the amplitude gets small enough that the sound is undetectable. A sound’s amplitude shrinks as it travels, but its speed remains constant.

The basic equation for constant speed motion (shown below) applies to sound.

[latex]d=vt[/latex]

In this equation, [latex]d[/latex] represents the distance traveled by the sound, [latex]t[/latex] represents the amount of time it took to go that distance and [latex]v[/latex] represents the speed.

Rule of thumb for lightning example

Example: thunder and lightning.

The rule of thumb for figuring out how far away a lightning strike is from you is this:

Count the number of seconds between when you see the lightning and hear the thunder. Divide the number of seconds by five to find out how many miles away the lightning hit.

According to this rule, what is the speed of sound in air? How does the speed of sound implied by this rule compare to 340 m/s?

Identify important physics concept :   This question is about speed of sound.

List known and unknown quantities (with letter names and units):

At first glance, it doesn’t look like there’s enough information to solve the problem. We were asked to find speed, but not given either a time or a distance. However, the problem does allow us to figure out a distance if we know the time- “Divide the number of seconds by five to find out how many miles away the lightning hit.” So, let’s make up a time and see what happens; if the time is 10 seconds, the rule of thumb says that the distance should be 2 miles.

[latex]v= \: ?[/latex]

[latex]d=2 \: miles[/latex]

[latex]t=10 \: seconds[/latex]

You might ask “Is making stuff up OK here?” The answer is YES! If the rule of thumb is right, it should work no matter what time we choose. (To check if the rule is OK, we should probably test it with more than just one distance-time combination, but we’ll assume the rule is OK for now).

Do the algebra:  The equation is already solved for speed. Move on to the next step.

Do unit conversions (if needed) then plug in numbers:  If you just plug in the numbers, the speed comes out in miles per second:

[latex]v = \frac{2 \: miles} {10 \: seconds}=0.2 \: \frac{miles} {second}[/latex]

We are asked to compare this speed to 340 m/s, so a unit conversion is in order; since there are 1609 meters in a mile:

[latex]v =0.2 \: \frac{miles} {second}*\frac{1609 \: meters} {1 \:mile}=320 \frac{m}{s}[/latex]

Reflect on the answer:

• The answer for speed from the rule of thumb is less than 10% off the actual value of roughly 340 m/s- surprisingly close!
• At the beginning, we assumed a time of 10 seconds. Does the result hold up for other choices? A quick check shows that it does! For instance, if we use a time of 5 seconds, the rule of thumb gives a distance of 1 mile, and the math still gives a speed of 0.2 miles/second. The speed will be the same no matter what time we pick. The reason is this:  The more time it takes the thunder to arrive, the farther away the lightning strike is, but the speed remains the same. In the equation for speed, both time and distance change by the same factor and the overall fraction remains unchanged.

Stop to think answers

• Both sounds take the same amount of time. (High and low pitched sounds travel at the same speed).
• Both sounds take the same amount of time. (Quiet sounds and loud sounds travel at the same speed).
• The sound of the whale travels the distance in less time- assuming sound from the whale travels in water and sound from the human travels in air. Sound travels faster in water than in air. (The info about frequency was given just to throw you off- frequency doesn’t matter).
• Wolfe, J. (2014, February 20). Properties of Sound. Retrieved from https://www.youtube.com/watch?v=P8-govgAffY ↵

Understanding Sound Copyright © by dsa2gamba and abbottds is licensed under a Creative Commons Attribution 4.0 International License , except where otherwise noted.

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How Far Does Sound Travel: The Science of Acoustics

Do you ever stop to think about how sound travels? It’s an interesting phenomenon that occurs everyday and yet we often take it for granted. In this blog post, we will explore the science of acoustics and how sound travels. We will answer the question of how far sound can travel and how it is affected by different factors. Stay tuned for an in-depth look at this fascinating topic!

Nature Of Sound

Sound is a mechanical wave that is an oscillation of pressure transmitted through some medium, such as air or water. Sound can propagate through solids and liquids better than gases because the density and stiffness are greater. So how far does sound travel? In this article we will answer how sound travels and how to calculate how far it travels in different scenarios.

Sound Transmits Conception

A common misconception with regard to how sound transmits itself between two points (for example from speaker to ear) is that the source creates waves of compression in the surrounding gas which then proceed on their way at a constant speed until they strike something else; either another solid object or our ears . This analogy might be okay for describing what goes on at low frequencies but once we go beyond around 1000 Hz, the propagation of sound becomes far more complex.

At low frequencies (below around 1000 Hz), sound waves tend to travel in all directions more or less equally and bounce off objects like a rubber ball would. As frequency increases however, the directivity of sound increases as well. So high-frequency sounds are more likely to travel in a straight line between two points than low frequencies. This is why we can often hear someone calling from some distance away when there is loud music playing – because the higher frequencies carry further than the lower ones.

How Far Can Sound Travel

There are three ways that sound can be transmitted: through air, through water, or through solids. The speed of sound through each medium is different and depends on the density and stiffness of the material.

The speed of sound through air is about 343 m/s (or 760 mph), and it travels faster in warmer air than colder air. The speed of sound through water is about 1500 m/s, and it travels faster in salt water than fresh water. The speed of sound through solids is much faster than through either gases or liquids – about 5000-15000 m/s. This is why we can often hear someone coming before we see them – the sound waves are travelling through the solid ground to our ears!

Now that we know how sound propagates and how its speed depends on the medium, let’s take a look at how to calculate how far it will travel between two points. We can use the equation

distance = speed x time

For example, if we want to know how far a sound will travel in one second, we have:

distance = 343 m/s x 0.001 s = 343 m

So sound travels 1 kilometer in roughly 3 seconds and 1 mile in roughly 5 seconds.

Does Вecibel Level affect the Sound Distance?

The surface area around a sound source’s location grows with the square of the distance from the source. This implies that the same amount of sound energy is dispersed over a larger surface, and that the energy intensity decreases as the square of the distance from the source (Inverse Square Law).

Experts of Acoustical control says, that

For every doubling of distance, the sound level reduces by 6  decibels  (dB), (e.g. moving from 10 to 20 metres away from a sound source). But the next 6dB reduction means moving from 20 to 40 metres, then from 40 to 80 metres for a further 6dB reduction.

How Far Can Sound Travel In Real World

In real world, there are many factors that can affect how far a sound travels. Factors such as air density, temperature and humidity have an impact on its propagation; obstacles like buildings or mountains could also block some frequencies from going through while letting others pass (this happens because at high frequencies they behave more like waves).

Sounds can propagate through solids better than they can propagate through air because their density/stiffness are greater (this means that sound travels faster). In addition to this, we also know that it takes less time for a high frequency wave to reach us from its source compared with low frequencies. For example if there’s some kind of obstacle blocking our path then it might take longer for waves at higher frequencies than those below 1000 Hz to past them.

Can Sound Waves Travel Infinitely?

No. The higher the frequency of a sound wave, the shorter its wavelength becomes. As wavelength decreases, the amount of energy in a sound wave also decreases and eventually it dissipates completely. This is why we often can’t hear someone calling from very far away when there’s loud music playing – because the high frequencies are being blocked out by all the noise!

Can Sound Travel 20 Miles?

The air may be permeable to these lower-frequency, sub-audible sound waves generated by elephants. Some whale species’ frequencies might travel through seawater for 1500 kilometers or 900 miles.

How Far Can a Human Scream Travel?

The normal intelligible outdoor range of the male human voice in still air is 180 m (590 ft 6.6 in).

The Guiness World Record of the Farthest distance travelled by a human voice belongs the Spanish-speaking inhabitants of the Canary Island of La Gomera, is intelligible under ideal conditions at 8 km (5 miles).

In Conclusion

At the end of this blog post, you should have a better understanding of how sound travel and what factors affect it. If you want to learn more about acoustics and sounds, you can check out our resources here.

• Why PS4 Is So Loud and How to Fix It
• Best Quiet Electric Toothbrush – Buyer’s Guide

Ocean Noise Pollution: What Is It?

Ways to Reduce Noise Pollution in Your Life

Top 8 Organizations Against Noise Pollution

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by Chris Woodford . Last updated: July 23, 2023.

Photo: Sound is energy we hear made by things that vibrate. Photo by William R. Goodwin courtesy of US Navy and Wikimedia Commons .

What is sound?

Photo: Sensing with sound: Light doesn't travel well through ocean water: over half the light falling on the sea surface is absorbed within the first meter of water; 100m down and only 1 percent of the surface light remains. That's largely why mighty creatures of the deep rely on sound for communication and navigation. Whales, famously, "talk" to one another across entire ocean basins, while dolphins use sound, like bats, for echolocation. Photo by Bill Thompson courtesy of US Fish and Wildlife Service .

Robert Boyle's classic experiment

Artwork: Robert Boyle's famous experiment with an alarm clock.

How sound travels

Artwork: Sound waves and ocean waves compared. Top: Sound waves are longitudinal waves: the air moves back and forth along the same line as the wave travels, making alternate patterns of compressions and rarefactions. Bottom: Ocean waves are transverse waves: the water moves back and forth at right angles to the line in which the wave travels.

The science of sound waves

Picture: Reflected sound is extremely useful for "seeing" underwater where light doesn't really travel—that's the basic idea behind sonar. Here's a side-scan sonar (reflected sound) image of a World War II boat wrecked on the seabed. Photo courtesy of U.S. National Oceanographic and Atmospheric Administration, US Navy, and Wikimedia Commons .

Whispering galleries and amphitheaters

Photos by Carol M. Highsmith: 1) The Capitol in Washington, DC has a whispering gallery inside its dome. Photo credit: The George F. Landegger Collection of District of Columbia Photographs in Carol M. Highsmith's America, Library of Congress , Prints and Photographs Division. 2) It's easy to hear people talking in the curved memorial amphitheater building at Arlington National Cemetery, Arlington, Virginia. Photo credit: Photographs in the Carol M. Highsmith Archive, Library of Congress , Prints and Photographs Division.

Measuring waves

Understanding amplitude and frequency, why instruments sound different, the speed of sound.

Photo: Breaking through the sound barrier creates a sonic boom. The mist you can see, which is called a condensation cloud, isn't necessarily caused by an aircraft flying supersonic: it can occur at lower speeds too. It happens because moist air condenses due to the shock waves created by the plane. You might expect the plane to compress the air as it slices through. But the shock waves it generates alternately expand and contract the air, producing both compressions and rarefactions. The rarefactions cause very low pressure and it's these that make moisture in the air condense, producing the cloud you see here. Photo by John Gay courtesy of US Navy and Wikimedia Commons .

Why does sound go faster in some things than in others?

Chart: Generally, sound travels faster in solids (right) than in liquids (middle) or gases (left)... but there are exceptions!

How to measure the speed of sound

Sound in practice, if you liked this article..., find out more, on this website.

• Electric guitars
• Speech synthesis
• Synthesizers

On other sites

• Explore Sound : A comprehensive educational site from the Acoustical Society of America, with activities for students of all ages.
• Sound Waves : A great collection of interactive science lessons from the University of Salford, which explains what sound waves are and the different ways in which they behave.

Educational books for younger readers

• Sound (Science in a Flash) by Georgia Amson-Bradshaw. Franklin Watts/Hachette, 2020. Simple facts, experiments, and quizzes fill this book; the visually exciting design will appeal to reluctant readers. Also for ages 7–9.
• Sound by Angela Royston. Raintree, 2017. A basic introduction to sound and musical sounds, including simple activities. Ages 7–9.
• Experimenting with Sound Science Projects by Robert Gardner. Enslow Publishers, 2013. A comprehensive 120-page introduction, running through the science of sound in some detail, with plenty of hands-on projects and activities (including welcome coverage of how to run controlled experiments using the scientific method). Ages 9–12.
• Cool Science: Experiments with Sound and Hearing by Chris Woodford. Gareth Stevens Inc, 2010. One of my own books, this is a short introduction to sound through practical activities, for ages 9–12.
• Adventures in Sound with Max Axiom, Super Scientist by Emily Sohn. Capstone, 2007. The original, graphic novel (comic book) format should appeal to reluctant readers. Ages 8–10.

Popular science

• The Sound Book: The Science of the Sonic Wonders of the World by Trevor Cox. W. W. Norton, 2014. An entertaining tour through everyday sound science.

Academic books

• Master Handbook of Acoustics by F. Alton Everest and Ken Pohlmann. McGraw-Hill Education, 2015. A comprehensive reference for undergraduates and sound-design professionals.
• The Science of Sound by Thomas D. Rossing, Paul A. Wheeler, and F. Richard Moore. Pearson, 2013. One of the most popular general undergraduate texts.

Text copyright © Chris Woodford 2009, 2021. All rights reserved. Full copyright notice and terms of use .

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Physics library

Course: physics library   >   unit 8, production of sound.

• Sound Properties: Amplitude, period, frequency, wavelength
• Speed of Sound
• Relative speed of sound in solids, liquids, and gases
• Mach numbers
• Decibel Scale
• Why do sounds get softer?
• Ultrasound medical imaging

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Since the speed of a wave is defined as the distance that a point on a wave (such as a compression or a rarefaction) travels per unit of time, it is often expressed in units of meters/second (abbreviated m/s). In equation form, this is

The faster a sound wave travels, the more distance it will cover in the same period of time. If a sound wave were observed to travel a distance of 700 meters in 2 seconds, then the speed of the wave would be 350 m/s. A slower wave would cover less distance - perhaps 660 meters - in the same time period of 2 seconds and thus have a speed of 330 m/s. Faster waves cover more distance in the same period of time.

Factors Affecting Wave Speed

The speed of any wave depends upon the properties of the medium through which the wave is traveling. Typically there are two essential types of properties that affect wave speed - inertial properties and elastic properties. Elastic properties are those properties related to the tendency of a material to maintain its shape and not deform whenever a force or stress is applied to it. A material such as steel will experience a very small deformation of shape (and dimension) when a stress is applied to it. Steel is a rigid material with a high elasticity. On the other hand, a material such as a rubber band is highly flexible; when a force is applied to stretch the rubber band, it deforms or changes its shape readily. A small stress on the rubber band causes a large deformation. Steel is considered to be a stiff or rigid material, whereas a rubber band is considered a flexible material. At the particle level, a stiff or rigid material is characterized by atoms and/or molecules with strong attractions for each other. When a force is applied in an attempt to stretch or deform the material, its strong particle interactions prevent this deformation and help the material maintain its shape. Rigid materials such as steel are considered to have a high elasticity. (Elastic modulus is the technical term). The phase of matter has a tremendous impact upon the elastic properties of the medium. In general, solids have the strongest interactions between particles, followed by liquids and then gases. For this reason, longitudinal sound waves travel faster in solids than they do in liquids than they do in gases. Even though the inertial factor may favor gases, the elastic factor has a greater influence on the speed ( v ) of a wave, thus yielding this general pattern:

Inertial properties are those properties related to the material's tendency to be sluggish to changes in its state of motion. The density of a medium is an example of an inertial property . The greater the inertia (i.e., mass density) of individual particles of the medium, the less responsive they will be to the interactions between neighboring particles and the slower that the wave will be. As stated above, sound waves travel faster in solids than they do in liquids than they do in gases. However, within a single phase of matter, the inertial property of density tends to be the property that has a greatest impact upon the speed of sound. A sound wave will travel faster in a less dense material than a more dense material. Thus, a sound wave will travel nearly three times faster in Helium than it will in air. This is mostly due to the lower mass of Helium particles as compared to air particles.  

The Speed of Sound in Air

The speed of a sound wave in air depends upon the properties of the air, mostly the temperature, and to a lesser degree, the humidity. Humidity is the result of water vapor being present in air. Like any liquid, water has a tendency to evaporate. As it does, particles of gaseous water become mixed in the air. This additional matter will affect the mass density of the air (an inertial property). The temperature will affect the strength of the particle interactions (an elastic property). At normal atmospheric pressure, the temperature dependence of the speed of a sound wave through dry air is approximated by the following equation:

where T is the temperature of the air in degrees Celsius. Using this equation to determine the speed of a sound wave in air at a temperature of 20 degrees Celsius yields the following solution.

v = 331 m/s + (0.6 m/s/C)•(20 C)

v = 331 m/s + 12 m/s

v = 343 m/s

(The above equation relating the speed of a sound wave in air to the temperature provides reasonably accurate speed values for temperatures between 0 and 100 Celsius. The equation itself does not have any theoretical basis; it is simply the result of inspecting temperature-speed data for this temperature range. Other equations do exist that are based upon theoretical reasoning and provide accurate data for all temperatures. Nonetheless, the equation above will be sufficient for our use as introductory Physics students.)

Look It Up!

Using wave speed to determine distances.

At normal atmospheric pressure and a temperature of 20 degrees Celsius, a sound wave will travel at approximately 343 m/s; this is approximately equal to 750 miles/hour. While this speed may seem fast by human standards (the fastest humans can sprint at approximately 11 m/s and highway speeds are approximately 30 m/s), the speed of a sound wave is slow in comparison to the speed of a light wave. Light travels through air at a speed of approximately 300 000 000 m/s; this is nearly 900 000 times the speed of sound. For this reason, humans can observe a detectable time delay between the thunder and the lightning during a storm. The arrival of the light wave from the location of the lightning strike occurs in so little time that it is essentially negligible. Yet the arrival of the sound wave from the location of the lightning strike occurs much later. The time delay between the arrival of the light wave (lightning) and the arrival of the sound wave (thunder) allows a person to approximate his/her distance from the storm location. For instance if the thunder is heard 3 seconds after the lightning is seen, then sound (whose speed is approximated as 345 m/s) has traveled a distance of

If this value is converted to miles (divide by 1600 m/1 mi), then the storm is a distance of 0.65 miles away.

Another phenomenon related to the perception of time delays between two events is an echo . A person can often perceive a time delay between the production of a sound and the arrival of a reflection of that sound off a distant barrier. If you have ever made a holler within a canyon, perhaps you have heard an echo of your holler off a distant canyon wall. The time delay between the holler and the echo corresponds to the time for the holler to travel the round-trip distance to the canyon wall and back. A measurement of this time would allow a person to estimate the one-way distance to the canyon wall. For instance if an echo is heard 1.40 seconds after making the holler , then the distance to the canyon wall can be found as follows:

The canyon wall is 242 meters away. You might have noticed that the time of 0.70 seconds is used in the equation. Since the time delay corresponds to the time for the holler to travel the round-trip distance to the canyon wall and back, the one-way distance to the canyon wall corresponds to one-half the time delay.

While an echo is of relatively minimal importance to humans, echolocation is an essential trick of the trade for bats. Being a nocturnal creature, bats must use sound waves to navigate and hunt. They produce short bursts of ultrasonic sound waves that reflect off objects in their surroundings and return. Their detection of the time delay between the sending and receiving of the pulses allows a bat to approximate the distance to surrounding objects. Some bats, known as Doppler bats, are capable of detecting the speed and direction of any moving objects by monitoring the changes in frequency of the reflected pulses. These bats are utilizing the physics of the Doppler effect discussed in an earlier unit (and also to be discussed later in Lesson 3 ). This method of echolocation enables a bat to navigate and to hunt.

The Wave Equation Revisited

Like any wave, a sound wave has a speed that is mathematically related to the frequency and the wavelength of the wave. As discussed in a previous unit , the mathematical relationship between speed, frequency and wavelength is given by the following equation.

Using the symbols v , λ , and f , the equation can be rewritten as

Check Your Understanding

1. An automatic focus camera is able to focus on objects by use of an ultrasonic sound wave. The camera sends out sound waves that reflect off distant objects and return to the camera. A sensor detects the time it takes for the waves to return and then determines the distance an object is from the camera. If a sound wave (speed = 340 m/s) returns to the camera 0.150 seconds after leaving the camera, how far away is the object?

Answer = 25.5 m

The speed of the sound wave is 340 m/s. The distance can be found using d = v • t resulting in an answer of 25.5 m. Use 0.075 seconds for the time since 0.150 seconds refers to the round-trip distance.

2. On a hot summer day, a pesky little mosquito produced its warning sound near your ear. The sound is produced by the beating of its wings at a rate of about 600 wing beats per second.

a. What is the frequency in Hertz of the sound wave? b. Assuming the sound wave moves with a velocity of 350 m/s, what is the wavelength of the wave?

Part a Answer: 600 Hz (given)

Part b Answer: 0.583 meters

3. Doubling the frequency of a wave source doubles the speed of the waves.

a. True b. False

Doubling the frequency will halve the wavelength; speed is unaffected by the alteration in the frequency. The speed of a wave depends upon the properties of the medium.

4. Playing middle C on the piano keyboard produces a sound with a frequency of 256 Hz. Assuming the speed of sound in air is 345 m/s, determine the wavelength of the sound corresponding to the note of middle C.

 Answer: 1.35 meters (rounded)

Let λ = wavelength. Use v = f • λ where v = 345 m/s and f = 256 Hz. Rearrange the equation to the form of λ = v / f. Substitute and solve.

5. Most people can detect frequencies as high as 20 000 Hz. Assuming the speed of sound in air is 345 m/s, determine the wavelength of the sound corresponding to this upper range of audible hearing.

Answer: 0.0173 meters (rounded)

Let λ = wavelength. Use v = f • λ where v = 345 m/s and f = 20 000 Hz. Rearrange the equation to the form of λ = v / f. Substitute and solve.

6. An elephant produces a 10 Hz sound wave. Assuming the speed of sound in air is 345 m/s, determine the wavelength of this infrasonic sound wave.

Answer: 34.5 meters

Let λ = wavelength. Use v = f • λ where v = 345 m/s and f = 10 Hz. Rearrange the equation to the form of λ = v / f. Substitute and solve.

7. Determine the speed of sound on a cold winter day (T=3 degrees C).

Answer: 332.8 m/s

The speed of sound in air is dependent upon the temperature of air. The dependence is expressed by the equation:

v = 331 m/s + (0.6 m/s/C) • T

where T is the temperature in Celsius. Substitute and solve.

v = 331 m/s + (0.6 m/s/C) • 3 C v = 331 m/s + 1.8 m/s v = 332.8 m/s

8. Miles Tugo is camping in Glacier National Park. In the midst of a glacier canyon, he makes a loud holler. He hears an echo 1.22 seconds later. The air temperature is 20 degrees C. How far away are the canyon walls?

Answer = 209 m

The speed of the sound wave at this temperature is 343 m/s (using the equation described in the Tutorial). The distance can be found using d = v • t resulting in an answer of 343 m. Use 0.61 second for the time since 1.22 seconds refers to the round-trip distance.

9. Two sound waves are traveling through a container of unknown gas. Wave A has a wavelength of 1.2 m. Wave B has a wavelength of 3.6 m. The velocity of wave B must be __________ the velocity of wave A.

a. one-ninth b. one-third c. the same as d. three times larger than

The speed of a wave does not depend upon its wavelength, but rather upon the properties of the medium. The medium has not changed, so neither has the speed.

10. Two sound waves are traveling through a container of unknown gas. Wave A has a wavelength of 1.2 m. Wave B has a wavelength of 3.6 m. The frequency of wave B must be __________ the frequency of wave A.

Since Wave B has three times the wavelength of Wave A, it must have one-third the frequency. Frequency and wavelength are inversely related.

• Interference and Beats

• Sound Waves
• Sound Vibration Propagation Of Sound

What Is Sound? Vibration and the Propagation of Sound

Have you ever used a musical instrument like a guitar, drum or violin? When we strike the strings of a guitar, we hear a sound. Same with the drum, when we hit a drum we hear a ‘thump’ sound. Also, how is one instrument able to create a wide variety of sounds? How does this happen? What is sound? How do we make a sound? How is the sound produced and about the propagation of sound?

What Is Sound?

A sound is a form of energy, just like electricity, heat or light. Sound is one of the important senses of the human body. Some sounds are pleasant, and some are annoying. We are subjected to various types of sound all time. Sound waves are the result of the vibration of objects. Let’s examine some sources of sounds like a bell. When you strike a bell, it makes a loud ringing noise. Now, instead of just listening to the bell, put your finger on the bell after you have struck it. Can you feel it vibrating? This is the key to sound. It is even more evident in guitars and drums. You can see the wires vibrating every time you pluck it. When the bell or the guitar stops vibrating, the sound also stops.

The to and fro motion of the body is termed vibration. You can see examples of vibrations everywhere. Vibrating objects produce sound. Some vibrations are visible; some aren’t. If you pull and then release a stretched rubber band, the band moves to and fro about the central axis and while doing, so it also produces a sound. The sound moves through a medium by alternately contracting and expanding parts of the medium it is travelling through.

In physics, the sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid.

Read More: Forms of Energy

Watch the video and learn about the fundamentals of sound

Sound Wave Characteristics

After understanding what is sound, let us study the characteristics of the sound wave. The distance between two consecutive peaks or troughs is termed as the wavelength of the wave or the period . The number of cycles per unit time is termed as the frequency of the sound . Frequency is measured in cycles per second or Hertz.

The faster an object vibrates, i.e. the higher the frequency, the higher the pitch of the sound. The difference between the voices of a man and a woman must be clearly evident to you. The voice of a man has a lower frequency which contributes to the deepness of the bass in the voice. Women, in contrast, have a voice with higher frequency resulting in a higher shrillness or pitch.

Closing Our Ears When We Hear Loud Noise

If you hear a very loud sound, what do you do? You cover your ears. How do you think that helps? When you cover your ears, you shut off the air inside your ears from the rest of the atmosphere. The sound waves travelling around you are now unable to get through to your ear or the intensity of the sound you hear is greatly reduced. Blocking your ears creates a discontinuity in the medium due to which the flow of sound energy is disturbed. Through this, we can make a very important observation; Sound waves rely on the medium for propagation. The propagation of the sound wave is not possible through the vacuum. The medium here can be gas, liquid or solid. The speed of sound when it is travelling through a medium depends on the type of medium. The speed of sound when travelling through air is 343 m/s or 1,235 km/h.

Speed of Sound

The speed of a sound wave is affected by the type of medium through which it travels. Sound waves travel the fastest in solids due to the proximity of molecules. Likewise, sound waves travel slowest in gases because gases are spread far apart from one another. The state of the medium through which sound travels is not the only factor that affects a sound’s speed. The speed of a sound wave can also be affected by the density, temperature, and elasticity of the medium through which the sound waves travel. Below is a table, we have listed the speed of sound in various materials.

Can Sound Travel in Space?

A medium is essential for the propagation of sound. Sound cannot travel through a vacuum because there are no molecules that can be compressed and expanded in space. Our voice is produced by the vibration of strings known as the vocal cords which are inside Adam’s apple. When you make a sound, its vibration travels through the air, and when it reaches your brain through your ears, it is interpreted as sound. In this case propagation of sound takes place through the air medium. How your brain and ear decode pressure variation in sound waves into sound is fascinating!

Human Hearing and Speech

Humans can hear sounds ranging from 20 Hz to 20 kHz. Sounds with frequencies above the range of human hearing are called ultrasound. Sounds with frequencies below the range of human hearing are called infrasound. The typical sound produced by human speech has frequencies in the order of 100 to 1,000 Hz.

Characteristics of Sound Waves

Reflection of Sound

Frequently Asked Questions – FAQs

List physical factors that affect sound propagation.

• 1. Atmospheric Turbulence: If the atmosphere in which the sound wave is travelling is turbulent, sound waves would scatter due to velocity fluctuations of the medium.
• 2. Wind Gradient: Sound propagating along the wind would bend downwards while sound propagating against the wind would bend upwards.
• 3. Temperature Gradient: Sound waves travel faster in a warm atmosphere near the surface of the earth. Here, there is upward refraction of sound waves. In case of a decrease in temperature at higher altitudes, the refraction would be downwards.

Which property of sound is affected by the change in temperature?

What waves are used in sonography, what do you mean by an echo, the below video helps to completely revise the chapter sound class 9.

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How to Measure Sound Travel in the Air

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Sound can travel through most materials -- the most commonly known being air (gas), water (liquid) and steel (solid). However, it does not travel at all in a vacuum, because the sound waves need some kind of medium in which to travel. In addition, some materials absorb, rather than reflect or pass, sound waves. This is the basis of soundproofing [source: Kurtus ].

The average speed of sound through air is about 1130 feet per second (344 meters per second) at room temperature. However, changes in temperature and humidity will affect this speed [source: Kurtus ].

Here is a simple way to measure the speed at which sound travels through air. You'll need the following items:

• Two blocks of wood, or other items that make a loud, sharp sound when struck together
• A stopwatch
• A friend to help with the experiment
• A tape measure

Instructions:

• Find a large empty area, such as a field or large court.
• Choose two spots on opposite ends of the area where each person will stand.
• Measure the distance between the two spots using a tape measure. Alternatively, you can count off measured steps between the two spots.
• Have your friend take the blocks and stand at one spot, holding them up high.
• Take the stopwatch and stand at the other spot. Make sure you have a clear view of the blocks.
• Signal your friend to bang the two blocks together hard.
• Start the stopwatch as soon as you see the blocks hit each other.
• Press stop as soon as you hear the sound from the blocks.
• Calculate the speed of the sound by dividing the distance between you and your friend by the elapsed time. To get a more accurate measurement, repeat the above steps a few times and then take an average of the results [source: Green Planet Solar Energy ]. //]]]]> ]]>

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NOTIFICATIONS

Sound in water.

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Prof John Montgomery, the head of Auckland University Leigh Marine Laboratory, explains how sound travels in water and how this is different to how sound travels in air. He explains why sound can travel so much further in the ocean compared to on land.

Point of interest: In this clip. you’ll hear the ‘song’ of the humpback whale. The humpback whale song is known to travel large distances through the ocean.

PROF JOHN MONTGOMERY Sound in the marine environment hasn’t been that well studied, but we know, I guess, from our original work where the question was, we know that fish can detect reefs, but how do they detect it? And our hypothesis was that it was based on sound. So we went and tested that, and found that larval fish do orient towards reef sounds, so we could record reef sound on a reef, take it out into a place where there wasn’t a reef and it would show up thinking there was a reef there. So that gives a really good indication of the likely importance of the soundscape, that it may be an important cue for animals in terms of migrations to reefs.

One of the real advantages of sound from a biological point of view is that there is a lot of it there and that it travels really well. So it can give you information about things that are happening from long distances away, and clearly that’s important for all sorts of biological activity.

The main difference between sound in air and sound in water is that air is a far less dense medium, so it doesn’t take much to move air, but sound attenuates reasonably quickly with distance and air, whereas under water, you need a sound that’s intense enough to move the water, which is quite dense and heavy, but it’s not very compressible so the sound then will propagate long distances.

In water, marine creatures can hear sound from vast distances and the extreme is probably the song of the humpback whale. and that sound can travel across whole oceans. so you could get, potentially, humpbacks at one end of the Pacific listening to humpbacks at the other.

Acknowledgement: Canadian Broadcasting Corporation Andrew Stevenson http://www.youtube.com/watch?v=eOS20plm7UM

Sound on the move

Sound is a pressure wave, but this wave behaves slightly differently through air as compared to water. Water is denser than air, so it takes more energy to generate a wave, but once a wave has ...

Hearing sound

Three components are needed for sound to be heard: A source – where the sound is made. A medium – something for the sound to travel through. A receiver – something to detect the sound. Source ...

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Speed of Sound Calculator

Table of contents

This speed of sound calculator determines the speed of sound in the air and water .

Not everybody knows about the sound speed dependence on the temperature – the higher the air temperature, the faster the sound can propagate.

To calculate the speed of sound in water , just choose the temperature – Fahrenheit °F or Celsius °C. You can also choose the desired unit – with this tool, you can find the speed of sound in mph, ft/s, or even knots!

Speed of sound in air

Air is almost an ideal gas. The formula for the speed of sound in ideal gases is:

• c c c – Speed of sound in an ideal gas;
• R R R – Molar gas constant, approximately 8.3145 J·mol −1 ·K −1 ;
• γ \gamma γ – Adiabatic index, approximately 1.4 for air;
• T T T – Absolute temperature; and
• M M M – The molar mass of the gas. For dry air is about 0.0289645 kg/mol

Substituting the values for air, we have the simplified formula for the speed of sound in m/s:

where T T T is in °C.

Did you notice something interesting? The speed of sound in the gas depends only on two constants – γ \gamma γ and R R R – and on the temperature but not on the air pressure or density, as it is sometimes claimed. The humidity of air also has an effect on the speed of sound, but the influence is so small that it can be neglected. The temperature is the only important factor!

Speed of sound in water

The most often used value is 1482 m/s (for 20 °C); however, an easy formula for the speed of sound in water doesn't exist. Many authors derived equations from experimental data, but the equations are complicated, and they always contain higher-order polynomials and plenty of coefficients.

The data in our calculator for speed in water comes from the speed of sound in water charts . The speed of sound in water is an important parameter in sonar research and acoustical oceanography. Nevertheless, the formula for seawater is even more complex as the speed of sound is also changing with the salinity.

💡 How about the speed of sound in solids? Well, our speed of sound in solids calculator can help you calculate it.

How to use the speed of sound calculator?

Let's calculate how the sound propagates in cold water – like really cold, from wintering swimming activities.

Choose the section you need – the speed of sound in water or air . It's water in our case, so we will use the bottom part of the calculator.

Pick the temperature unit . Let's take degrees Fahrenheit.

Select the temperature from a drop-down list . Take this freezingly cold 40 °F.

The speed of sound calculator displays the speed of sound in water ; it's 4672 ft/s.

Let's compare it with 90 °F (warm bath temperature). The speed is equal to 4960 ft/s this time. Remember that you can always change the units of speed of sound: mph, ft/s, m/s, km/h, even to knots if you wish to.

Now, as you know the speed, calculate the time or distance with this speed calculator . Also, you can check how far the storm is with our lightning distance calculator – the speed of sound in air is a significant factor for that calculations.

How do I calculate the speed of sound in air given temperature?

To determine the speed of sound in air, follow these steps:

• If you're given the air temperature in °C or °F, you need to first convert it to kelvins .
• Add 1 to the temperature in kelvins and take the square root .
• Multiply the result from Step 2 by 331.3 .
• You've just determined the speed of sound in the air in m/s – congrats!

How does the speed of sound change with temperature?

The speed of sound increases as the air temperature increases. The precise formula is:

c_air = 331.3 × √(1 + T/273.15) ,

where T is the air temperature in °C. This formula returns speed in m/s.

What is the speed of sound in air?

Assuming the air temperature of 20 °C, the speed of sound is:

• 343.14 m/s;
• 1235.3 km/h;
• 1125.8 ft/s; or

You can derive these results by applying the formula c_air = 331.3 × √(1 + T/273.15) , where T = 20°C. The result is in m/s, and then, if needed, you have to convert it to other speed units.

What is the speed of sound in water?

Assuming the water temperature of 20 °C, the speed of sound is:

• 4859 ft/s; or

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Reflecting on the Journey

Does sound travel up or down noise guide.

Let’s address the main question: Does sound travel up or down? In reality, sound doesn’t have a fixed direction of travel like light, which travels in straight lines. Sound waves radiate out in all directions from their source.

• September 25, 2023

Home » Blog » Does sound travel up or down? Noise Guide

Sound is like an exquisite tapestry that winds its way through our lives. We can’t see it, but it’s always with us.

There are sound waves all around us all the time, from the birds singing in the morning to the soothing music we listen to.

In the middle of this sound symphony, though, an interesting question comes up: does sound have a set path that it follows, going up or down?

In this blog, we’ll start a trip to figure out the mysteries of sound waves by looking into how they travel and breaking down the puzzle of their direction.

Explore the fascinating world of sound with us. This is where science meets magic, and sometimes the answers aren’t as simple as they seem.

The Nature of Sound Waves

To understand how sound moves, you need to know the basics of sound waves . Sound is a type of mechanical wave that moves through a medium, like air but also things and liquids. 

The vibrations of things, like voice cords, musical instruments, or even the sound of thunder during a storm, make these waves.

Compressions and rarefactions make up sound waves. Compressions are places where the medium’s particles are close to each other, while rarefactions are places where the particles are far apart. 

Since these changes in pressure travel through the medium, they make sound when they reach our ears.

Does sound travel up or down?

Sound doesn’t have a fixed direction of travel like a projectile or a ray of light. Instead, sound waves propagate outward spherically from their source in all directions, creating a three-dimensional sphere of expanding waves. 

This means sound moves in every direction at the same time, including up, down, sideways, and all other directions you can think of. 

If you throw a stone into a still pond, the waves will move outward in a circle, not just up and down. In the same way, sound waves spread out from their source and fill the space around them. 

The way our ears pick up a sound, on the other hand, gives us an idea of its direction. Our brains use the small difference in time between when a sound hits each ear and the difference in sound intensity to figure out where the sound is coming from. 

This lets us know if it’s above, below, or somewhere else in our environment. In other words, sound travels in all directions, but our hearing and the surroundings affect where we think it came from.

Types of Sound & How Each Sound Types Works

Sound is a complex and diverse phenomenon, and it can be categorized into various types based on several characteristics and properties. Here, we’ll explore the primary types of sound:

Audible Sound:

Audible sound is any sound that falls in the 20 Hz to 20,000 Hz frequency band that humans can hear. In a medium, like air, pressure waves move through it and make it work. 

When an item vibrates, it causes the molecules of air around it to compress and expand. 

These changes in air pressure move through the air like waves, hitting our ears and making our eardrums tremble. 

Next, our inner ear turns these movements into electrical signals. These signals are sent to the brain to be interpreted as sound.

Infrasound:

Infrasound is made up of sound waves with frequencies below 20 Hz, which is the lowest frequency that humans can hear. Infrasound is often made by natural events like meteorites hitting Earth, earthquakes, and volcanic fires.

It can also come from things that people make, like industry machinery. Even though we can’t hear infrasound, it can have an effect on our bodies because it can make different structures vibrate and resonate.

Ultrasound:

Ultrasound uses sound waves with levels above 20,000 Hz, which are higher than what the human ear can pick up. Ultrasound sounds are sent into the body by a transducer, which is used in medical imaging. 

These waves hit organs and other parts of the body inside the body and then go back to the transducer to be turned into pictures. In medicine, ultrasound is used for non-invasive screening and diagnosis. In industry, ultrasound is used to find flaws and measure them.

White Noise:

White noise is a random signal that is the same strength at all levels that humans can hear. 

It makes a constant sound that sounds like static or “shushing” by mixing sound waves with different frequencies and amplitudes. 

White noise is often used to block out other sounds that aren’t needed, to help people relax, or to help them concentrate.

Pink Noise:

While pink noise is like white noise, it has more energy in the lower levels. As the frequency goes up, the loudness of the higher-frequency parts goes down, making it. 

Pink noise is used to test and calibrate audio because it has a more even sound range.

Brownian Noise (Brown Noise):

Compared to pink noise, brownian noise has even more energy in the low levels. It is made by making the lower-frequency parts louder as the frequency goes down. 

The sound of brownian noise is often heavy and rumbling, and it is sometimes used to help people relax and sleep.

Musical Sound:

The structured vibrations of musical instruments, such as strings, air columns, or membranes, produce sound. Based on its physical properties, an instrument produces particular frequencies or harmonics when it is played. 

Melodies and harmonies can be produced by combining the musical notes that are produced by these vibrations. The way these frequencies are arranged and interact is a major factor in how we perceive music.

Speech is a type of sound that people make to communicate. It requires exact synchronization of the respiratory system, tongue, lips, and vocal cords. 

Vocal cord vibrations and airflow are adjusted to create various speech sounds, or phonemes, which are then articulated into words and sentences. 

The physiology of speech generation and the language processing abilities of our brains work together to produce the tremendously complex speech that is human.

Environmental Sounds:

Environmental noises are a wide range of sounds that are produced by nature around us. These noises come from a variety of sources, including machines, weather, animals, and more. 

The features of these entities are contingent upon the particular source and the propagation channel.

In addition to giving us information about our surroundings and affecting our mood and emotions, ambient sounds are essential to our sensory experience.

Electronic Sounds:

Synthesizers and other electronic equipment are used to artificially create electronic sounds. These gadgets generate electrical impulses, which speakers or headphones then translate into sound waves. 

Electronic sounds are adaptable and can be used in a variety of media and entertainment, including music, movies, video games, and other forms of entertainment because their frequencies, amplitudes, and waveforms can be precisely adjusted.

How We Perceive Sound Direction

Our ears are amazing devices that are made to pick up sound coming from a variety of sources. Because our two ears are on different sides of our head, we can distinguish between variances in the sound’s loudness and arrival time to establish the direction of a sound source.

Time Difference: Sound travels significantly faster to the closest ear when it comes from a source that is closer to that ear than the other. The direction of the sound source is established by our brain using this time difference.

Difference in Intensity: An ear that is nearer the source of the sound will pick up a louder sound wave than an ear that is farther away. This variation in intensity is used by our brain to enhance our understanding of sound direction.

To put it simply, our ears triangulate the direction of a sound source in order to tell us if it is coming from above, below, in front of us, or behind us.

Why does sound seem to travel upward more easily than it does horizontally?

Sound perception often gives the impression that it travels upward more easily than horizontally due to a combination of factors related to the environment, human anatomy, and the physics of sound propagation.

Acoustic Reflection and Refraction

The way that sound waves interact with their environment is one of the main reasons that sound seems to move upward more readily than horizontally. 

Sound waves have a tendency to reflect and bounce off of flat surfaces like floors, walls, and ceilings in different directions. 

Sound waves, for example, frequently bounce off of ceilings and can be deflected downward, giving the impression that sound is coming from above. 

Particularly in small areas, this sound reflection and refraction can give the impression that noises are coming from above.

Human Ear Anatomy

The idea that sound travels upward can also be attributed to the structure of the human ear . Owing to their slightly elevated position on the sides of the head, our ears are inherently more perceptive to noises coming from above than from below. 

We can find sound sources thanks to this anatomical arrangement, which enables us to notice minute differences in sound arrival timings and intensities between our ears. 

Because our ears are sensitive to upward-oriented sound signals, even when sound waves are moving horizontally, they may appear to be coming from above.

Atmospheric Conditions

The path that sound takes can be affected by atmospheric conditions. At different elevations, variations in temperature and wind speed can cause sound waves to refract, or bend. 

It may be believed that sound moves more readily upward in specific weather situations because of this refraction, which can lead sound to travel in unexpected ways, including upward.

Unlike a laser beam of light, sound is a fascinating phenomenon that is not limited to one direction of propagation. Rather, sound waves travel in all directions at once, enveloping us in a complex auditory landscape. Our ears assist us in determining the direction of sound sources because of their remarkable capacity to distinguish variations in sound arrival timings and intensities.

Thus, keep in mind that sound is all around you and that your ears are cooperating to help you identify the source of those sounds the next time you hear a bird singing in a tree, a car horn honking, or your favorite song playing on your headphones.

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About author.

Muhaiminul is the insightful article’s author on Quiethall.com and a fervent DIY living enthusiast. Muhaiminul has spent countless hours learning about and exploring the world of soundproofing techniques and products because he has a deep fascination with creating peaceful and noise-free spaces. Muhaiminul shares helpful advice, detailed how-to guides, and product reviews on Quiethall.com out of a desire to help others cultivate peace in their lives.

Muhaiminul Anik

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Can Humans Hear Sound in Space?

• An Introduction to Astronomy
• Important Astronomers
• Solar System
• Stars, Planets, and Galaxies
• Space Exploration
• Weather & Climate
• Ph.D., Physics and Astronomy, Purdue University
• B.S., Physics, Purdue University

Is it possible to hear sounds in space? The short answer is "No." Yet, misconceptions about sound in space continue to exist, mostly due to the sound effects used in sci-fi movies and TV shows. How many times have we "heard" the starship Enterprise or the Millennium Falcon whoosh through space? It's so ingrained our ideas about space that people are often surprised to find out that it doesn't work that way. The laws of physics explain that it can't happen, but often enough producers don't really think about them. They're going for "effect."

Plus, it's not just a problem in TV or movies. There are mistaken ideas out there that planets make sounds , for example. What's really happening is that specific processes in their atmospheres (or rings) are sending out emissions that can be picked up by sensitive instruments. In order to understand them, scientists take the emissions and "heterodyne" them (that is, process them) to create something we can "hear" so they can try to analyze what they are. But, the planets themselves aren't making sounds.

The Physics of Sound

It is helpful to understand the physics of sound. Sound travels through the air as waves. When we speak, for example, the vibration of our vocal cords compresses the air around them. The compressed air moves the air around it, which carries the sound waves. Eventually, these compressions reach the ears of a listener, whose brain interprets that activity as sound. If the compressions are high frequency and moving fast, the signal received by the ears is interpreted by the brain as a whistle or a shriek. If they're lower frequency and moving more slowly, the brain interprets it as a drum or a boom or a low voice.

Here's the important thing to remember: without anything to compress, sound waves can't be transmitted. And, guess what? There's no "medium" in the vacuum of space itself that transmits sound waves. There is a chance that sound waves can move through and compress clouds of gas and dust, but we wouldn't be able to hear that sound. It would be too low or too high for our ears to perceive. Of course, if someone were in space without any protection against the vacuum, hearing any sound waves would be the least of their problems. 

Light waves (that aren't radio waves) are different. They do not require the existence of a medium in order to propagate. So light can travel through the vacuum of space unimpeded. This is why we can see distant objects like planets , stars , and galaxies . But, we can't hear any sounds they might make. Our ears are what pick up sound waves, and for a variety of reasons, our unprotected ears aren't going to be in space.

Haven't Probes Picked Up Sounds From the Planets?

This is a bit of a tricky one. NASA, back in the early 90s, released a five-volume set of space sounds. Unfortunately, they were not too specific about how the sounds were made exactly. It turns out the recordings weren't actually of sound coming from those planets. What was picked up were interactions of charged particles in the magnetospheres of the planets; trapped radio waves and other electromagnetic disturbances. Astronomers then took these measurements and converted them into sounds. It is similar to the way that a radio captures the radio waves (which are long-wavelength light waves) from radio stations and converts those signals into sound.

Why Apollo Astronauts Report Sounds Near the Moon

This one is truly strange. According to NASA transcripts of the Apollo moon missions, several of the astronauts reported hearing "music" when orbiting the Moon . It turns out that what they heard was entirely predictable radio frequency interference between the lunar module and the command modules.

The most prominent example of this sound was when the Apollo 15 astronauts were on the far side of the Moon. However, once the orbiting craft was over the near side of the Moon, the warbling stopped. Anyone who has ever played with a radio or done HAM radio or other experiments with radio frequencies would recognize the sounds at once. They were nothing abnormal and they certainly didn't propagate through the vacuum of space. 

Why Movies Have Spacecrafts Making Sounds

Since we know that no one can physically hear sounds in the vacuum of space, the best explanation for sound effects in TV and movies is this: if producers didn't make the rockets roar and the spacecraft go "whoosh", the soundtrack would be boring. And, that's true. It doesn't mean there's sound in space. All it means is that sounds are added to give the scenes a little drama. That's perfectly fine as long as people understand it doesn't happen in reality. 

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Robb Report Audio Awards 2024: The 40 Best Headphones, Earbuds, Speakers, Turntables, and More

Robb report editors and writers test hundreds of the finest audio products in the world every year. we've mined those reviews to name the best audiophile gear of 2024..

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Pronouncing anything the “Best of”—whether it’s an automobile, a wine, or a stereo system—is as much about personal taste as it is about price and specifications. In the spirit of our inaugural 2023 Audio Awards, the Robb Report editors have compiled this group of recommended components based on the high value, quality, and performance each delivers compared to the very best and most costly available. While lunatic-fringe audiophiles (and that includes some from these ranks) regularly audition so-called state-of-the-art gear, we take particular pleasure in recommending those components whose performance far outdistances their price tags. While you won’t see any $800,000 loudspeakers or $500,000 turntables here, we guarantee that all the components listed will acquit themselves admirably when performing the task for which each was designed, even against the “big guns.” While some brands are household names, we have also been quick to share special products whose footprint has never been seen in a big box store. Especially worth seeking out, think of these as a “secret handshake” between audiophile friends.

Best Floor-Standing Loudspeakers: Sonus faber Stradivari G2

The Stradivari Second Generation evolved from the original Stradivari, launched in the early 2000s, and features a wide front baffle, which is partially responsible for this speaker’s organic, natural, and full-bodied sound. A pair of 10-inch woofers go down to 25 Hz, while the six-inch, Neodymium magnet midrange driver handles the lion’s share of the sound for which the Italian manufacturer is famous. From 160 Hz to 2,200 Hz, this driver is the speaker’s heart and soul, aided in its role by a one-inch soft-dome tweeter. Though relatively sensitive at 92 dB, a high-current amplifier with at least 100 watts will go a long way toward making the Stradivari G2s sing. As with every Sonus faber loudspeaker, the wooden cabinetry is exquisite beyond belief. — Robert Ross

Best Loudspeakers for Design Obsessives: Songer Audio S1

A tour de force of technology, craftsmanship, and unbelievably lifelike sound, this 47-inch-tall tower is a dream come true for lovers of low-power tube amps. Amazingly, it uses only one driver, mounted at ear-level in a 120-pound bass-reflex enclosure constructed in a choice of hardwoods and embellished with polished brass details. There is a magic to the sound because of this speaker’s handmade, full-range transducer and the way that it reproduces music with the speed, transparency, and impact of a real performance. A time-aligned point-source, the response across the frequency spectrum is coherent in a way that no multi-driver system can be. Non-fatiguing and transparent, the sound can be compared to Quad 57 electrostatics, but with much greater weight and presence. For the music lover who wears “made to measure.” — RR

Best Stand-Mount Loudspeakers: Aretai Contra 100S

Winner of the prestigious Red Dot Design Award for product design in 2022, the smallest member of the Contra family combines sonic, aesthetic, and engineering principles that embody what designer Janis Irbe calls “the Northern Sound concept—the crisp and vital freshness of a winter morning surrounded by the generous and robust vastness of Nature.” However you characterize the sound of the Latvian-made loudspeaker, it comes with prodigious bass down to 30 Hz, thanks to a rear-firing six-inch woofer that complements its front-firing twin. The novel waveguide for the neodymium tweeter extends response to beyond 25 kHz but importantly replicates a deep, wide soundstage. These are serious speakers, with optional bi-wiring/bi-amping capability, and vacuum-tube lovers will appreciate the valve-friendly impedance and sensitivity of the Contra 100S. — RR

Best Bookshelf Loudspeakers: Graham Audio LS3/5A

When space is as precious as perfectionist sound, there are few if any loudspeakers more satisfying than the shoe-box-sized LS3/5A. The British Broadcasting Corporation’s original mini-monitor is a true audio icon and has remained in production since the first one was made in 1975 under license from the BBC. Since then, more than a dozen manufacturers have built the little giant slayer, and today, one top choice is Graham Audio’s Chartwell LS3/5A. Set up for nearfield listening on a desktop or bookshelf, the two-way design uses a five-inch Bextrene-cone midrange/woofer and a .75-inch mylar-dome tweeter. They don’t play at ear-bleeding levels and don’t go much below 70 Hz, but for tonal accuracy and their ability to sound like real voices and music, this classic product should be a part of every audiophile’s life experience. — RR

Best Bang-for-the-Buck Loudspeakers: JBL L100 Classic

The JBL L100 came on the scene in 1970. Those of us old enough may remember the Memorex print ad showing a guy in a Le Corbusier chair with his hair blown back by a single L100, implying that Memorex tape created a simulacrum of a real performance. While the Quadrex foam-grilled icon blasting the longhair is probably junk today, it’s possible to buy a vastly improved (but identical-looking) version of JBL’s enduring icon more than half a century later. The L100 Classic’s all-new 12-inch woofer, 5.25-inch midrange, and 1-inch titanium-dome tweeter improve on every aspect of the original’s sound, yet express the same youthful exuberance that pumped Stones, Hendrix, and Cream into smoke-filled dorms way back when. Buy a pair and go back in time. — RR

Best Wi-Fi Loudspeakers: KEF LS60 Wireless

Still the choice for those seeking exceptional sound and clean design, the KEF LS60, a floor-standing loudspeaker with about the narrowest form factor imaginable, has everything including the streamer built into it. Digital and analog sources can be plugged into the back panel of the master speaker, allowing this full-featured system to serve up superior sound, thanks largely to the Uni-Q front driver that delivers an incredibly coherent “point-source,” yet evenly one dispersed throughout the room. Impressive bass response comes from four 5.25-inch woofers in each enclosure, and 1,400 watts of Class D amplification shared between both speakers. Architectural colors for cabinets and drivers make these the perfect choice for midcentury design-types. — RR

Best Portable Wi-Fi Loudspeaker: Bang & Olufsen Beosound Level

Life is too short to bring bad design into one’s home. Thankfully, there is an antidote, and it sounds fantastic. Bang & Olufsen’s Beosound Level offers an immense portable soundscape and versatility to match. Only slightly larger than a legal pad and about two inches in depth, this Bluetooth-enabled Wi-Fi speaker streams music with rich, room-filling sound. Battery operated, the Level stands up, lays flat, or hangs on a wall. It can be carried from room to room, and, because it’s dust and splash-resistant, can even take its talents outdoors. Whether it’s the primary system for a smaller space or a musical sidekick for leisure listening, this is a sonic and aesthetic overachiever in the world of wireless speakers. We named it “Best Portable” last year and still, nothing does it better than the Beosound Level. — RR

Best Portable Digital Audio Player: Astell&Kern A&ultima SP3000T

Astell&Kern’s digital audio players (DAP) are pocket-sized devices capable of storing and playing high-resolution music or media files. The A&ultima series of flagship players reproduce the ultimate high-res sound for use with headphones or in-ear earphones, like the company’s $4,999 Novus. The just-released SP3000T is based on the acclaimed SP3000 but adds the warmth and delicacy of tube amplification with A&K’s Triple Amp System, which allows users to customize their sound profile using tube amplification, a digital op-amp, or a hybrid combination of both tube and op-amps. The integration of dual Raytheon mil-spec vintage vacuum tubes creates an authentic analog sound, while the screen can display digital VU meters for added nostalgia to the musical journey. All three modes are available when using the 2.5 mm, 3.5 mm or 4.4 mm outputs.

Best Wireless Headphones: Sony WH-1000XM5

The Sony name may lack the glamour of some of the other brands on this list, but the Japanese electronics giant have repeatedly put out some of the best overall headphones you can buy over the last few decade. Of those, our pick is the current flagship over-ear model, the WH-1000XM5. They’re lightweight, comfortable, and much sleeker than the majority of their peers. They also offer active noise cancellation that it is a very clear step up from their predecessor, the also-excellent WH-1000XM4. Their best feature, though, is their audio quality. From the moment you turn them on, these cans sound superb, whether you’re a fan of classical, pop, or house. Even if their sound profile is a little bass-heavy for you, Sony’s easy-to-use app has an equalizer that’ll allow you to tweak settings to your heart’s content. The WH1000XM5 also offer excellent call quality and a useful voice-activated awareness mode—which pauses music and turns on the exterior microphones when someone is speaking to you—making them well suited to both work and play. — Bryan Hood

Best Wired Headphones: Focal Clear MG

It’s easy to be skeptical of some of the claims that audiophiles make. With budget and mid-priced headphones sounding as good as they do these days, is premium audio really worth the significant jump in cost? Just take a listen to your favorite album on Focal’s Clear MG and you’ll understand why sound snobs are so adamant about the difference between their gear and everything else. The French brand’s over-ears sound so pristine that you’ll understand what all the fuss is about within a song or two. Sure, they cost significantly more than some of the other cans on this list, but you won’t care one bit once you start noticing new details in a record you’ve already devoured dozens of times before. There aren’t many headphones that will give you the sense that you’re listening to an artist perform live every time you press play—but the Clear MG will. — BH

Best Headphones for Audiophiles: Meze Empyrean II

Because a $12,000 electrostatic headphone rig may not be every music lover’s cup of audiophile tea, we can be thankful for the new Meze Empyrean II. While hardly inexpensive, these Romanian-designed-and-built headphones are as satisfying to listen to as they are comfortable for long listening sessions. The aluminum housings are precision CNC-milled aluminum, with black metal grilles whose pattern of arched perforations recalls a fine Art Deco motif. The drivers, which use a planar diaphragm sandwiched between two perforated, fiberglass-infused pieces of lightweight ABS, are two reasons the sound of the Empyrean II is so natural, detailed, and impactful. The frequency response is, almost literally, off the charts, extending from a subterranean eight Hz and spiraling to a (literally) unheard of 110,000 Hz. Altogether, the Empyreans hit the headphone sweet spot and beg the question, “How much better can headphones get?” — RR

Best Designed Headphones: Apple AirPods Max

It’s no secret that the vast majority of headphones look pretty much the same. But not the AirPods Max. The over-ear version of Apple’s ubiquitous wireless earbuds has been one of the best-looking options on the market since its introduction earlier this decade. The stylish cans have the clean, streamlined look we’ve come to expect from the brand since the mid-aughts, with the added bonus of coming in a wide array of colors. The headphones’ smooth anodized aluminum cups don’t just look (and feel) good, they also that rotate independently of one another to keep pressure balances on your head, which is crucial since they are on the heavy side. Design and color options aren’t the only thing that separate the AirPod Max from the company’s earbuds—they also deliver excellent, well-balance audio performance regardless of what you’re listening to. Noise cancelling is fantastic, and their ease of use, especially if you already use other Apple products, just cannot be beat. — BH

Best Noise-Cancelling Headphones: Bose QuietComfort Ultra

Sometimes you just need to block out your surroundings. Whether you’re trying to focus on a particular task or just need some peace and quiet, it’s always a good idea to have a dependable pair of noise-cancelling headphones nearby. No company has proven itself more reliable on this front than Bose and its newest flagship over-ears, the QuietComfort Ultra, take things to a new level. These things can block out—or at least greatly quiet down—basically all environmental noise allow you’re likely to come across on a daily basis. You may still hear that jackhammer down the block, but it won’t be anywhere near as annoying. They also offer Bose’s typically solid audio performance and significantly better transparency than their predecessors, the Noise Cancelling Headphones 700. Add in a pleasing makeover and one of the best pairs of headphones just got better. — BH

Best Gaming Headphones: Razer BlackShark V2 Pro

Buying headphones for gaming is little different than buying them for basically any other activity. They need to sound good, of course—the last thing you want is to miss someone sneaking up behind you during a tense death match—but they also need to be lightweight and comfortable enough to accommodate marathon gaming sessions. That’s what we like so much about Razer’s BlackShark V2 Pro headphones: You’ll basically forget you’re wearing them. They also have a quality plug-in mic, so you can communicate with all the members of your team—or talk a little trash—without any noticeable lag. Just as important as all this, though, might be how normal they look. Gamer-focused gear has a tendency stand out a little too much, but not the BlackShark V2 Pros. In fact, with the exception of their serpentine logo and mic, they look just like any other pair of premium headphones. You might not even mind being spotted in them during your morning commute. — BH

Best Headphones for Travel: Bang & Olufsen Beoplay H95

You’ll want a pair of headphones that can do it all if you’re constantly on the go. The Bang & Olufsen Beoplay H95 falls firmly into this camp. The Danish audio experts’ top-of-the-line cans offer some of the best sound you’ll find at their price level. Custom titanium drivers produce audio that is rich, lively, and, most important of all, detailed. An array of exterior microphones and an active noise-cancellation chip make constant adjustments so you can actually hear what you’re listening to, even in noisier environments like a train car or airplane cabin. Both volume and noise cancellation levels can be adjusted via dials conveniently worked into each cup. They also have lambskin earpads, leather headband, and an aluminum frame available in a rainbow colors (chestnut brown might be our favorite) so you’re guaranteed to travel in style. — BH

Best Earbuds: Bose QuietComfort Ultra Earbuds

It’s amazing what a few key tweaks can do. The new Ultra QuietComfort Earbuds aren’t all that different than their immediate predecessors, the QuietComfort Earbuds II, but they offer better call quality and a new immersive audio mode. The two upgrades may not sound like much in isolation, but are actually game changers that fix two of the ‘buds most apparent flaws. Unsurprisingly, this year’s model continues to deliver the solid audio performance you expect from a Bose product. Purists tend not to love audio processing, but Immersive Sound adds life and depth to pop and electronic music. The earbuds’ biggest virtues, though, remain their fit and noise cancellation ability. A variety of comfortable tips and wings provides a seal that can be hard to get from other in-ear headphones. Noise cancellation, meanwhile, remains superlative whether you just need some quiet or want to better focus on the detail of your favorite sonata while riding the subway. — BH

Best Sounding Earbuds: Sennheiser Momentum True Wireless 4

It can be easy to forget these days, but most people buy headphones (whether in- or over-ear) to listen to music. And when it comes to earbuds, there aren’t any that sound than the Sennheiser Momentum True Wireless 4 right now. The German outfit’s latest feel like an evolutionary leap forward, finally delivering the warm and precise sound the brand is known for in a pair of earbuds. It doesn’t matter what kind of music you love, be it alt-country, bebop, neo-classical, grime, or house: Each recording sounds the way its producer intended it to, which is no mean feat. There’s more to these earbuds than superlative audio quality, though. They also feature feature a redesigned antennae that improve connection reliability—which was a significant issue of their predecessors—and call quality been given a boost. And when you’re more concerned with blocking sound out than listening to anything, their noise cancellation is solid. They’re also lightweight and comfortable, which is good news if you feel like listening to a particularly epic double album. — BH

Best Noise-Cancelling Earbuds: Sony WF-1000XM5

Sony’s latest flagship earbuds, the WF-1000XM5, offer the company’s best noise-cancelling performance. Even on a noisy subway you’ll be able to listen to your favorite song or podcast without trouble. But you won’t just hear them clearly: You’ll also be able to make out all the detail you would listening in a quiet room, whether it be the quaver in someone’s voice or the texture of a guitar solo. These in-ear headphones utilize a redesigned array of six microphones and two processors to take in and then block out the most distracting parts of the world around you. We were most impressed by how well they blocked out wind, something anyone who’s tried to take a call while walking can tell you that most earbuds struggle with. Part of the reason they’re so adept at blocking out unwanted noise is that they’re smaller than their predecessors, the WF-1000XM4, and come with foam ear tips, which makes it easier than ever before to get nice snug fit. Add in Sony’s typically excellent audio quality and you have yourself one of the better all-around pair of earbuds you can buy.— BH

Best Earbuds for Working Out: Bose Ultra Open Earbuds

Here’s the rare pair of earbuds (or headphones, if you want to broaden things) that feel like something completely new. Bose’s new Ultra Open Earbuds are like nothing we’ve tried before. Rather than fitting them into your ear canal like you do so many other earbuds, you simply clip these onto your earlobes. The ear-clinging design is unorthodox, but it works shockingly well. The small speaker on each bud projects music into your ear that you can still hear perfectly well while being aware of your surroundings (though it does mean you may have to turn the volume up in loud areas). This makes them particularly well-suited for working out in public, especially if you want to be aware of that car coming up behind you on your run. Don’t worry about the Ultra Open earbuds slipping off, either. The clip mechanism is as secure as it is comfortable, and you can wear these for hours without experiencing any discomfort. — BH

Best-Designed Earbuds: Beats Studio Buds +

Sometimes simplicity is the truest elegance. The latest version of Beat’s Studio Buds are easily the most streamlined earbuds currently on market. Unlike their corporate cousins, the Apple AirPods and AirPods Pro, these don’t have stems, and it’s actually hard to tell you’re even wearing in-ear headphones when you have them in. Even the case looks slick, especially if you opt for the transparent pair (which, if you ask us, you definitely should). State-of-the-art design isn’t all about looking good, though. These earbuds are extremely lightweight, so they’re comfortable to wear, even for long periods of time. Even the touch controls are intuitive, as is using them with any Apple device. Sound quality isn’t spectacular, but it’s better than solid whether you’re listening to music or making calls, which will do for most of us. — BH

Best Earbuds for Travel: Apple AirPods Pro (2nd Generation)

At first listen, it can be easy to wonder why Apple’s AirPods Pro are as ubiquitous as they are. The second iteration of the ultra-popular earbuds sounds good but by no means stellar. The same goes for their noise-cancelling technology and fit. What is singular about them, though, is an ease of use that no other headphone—except their bigger sibling the Airpods Max—can claim, especially if you’re already part of the Apple ecosystem (as many of us are). Simply pop the Airpods in and you’re connected to your iPhone. They don’t have multi-point, but even switching between devices is a breeze (just open up the Bluetooth menu and click). Traveling is stressful enough, so why not pack a pair of earbuds that you’ll be able to connect to any of the devices you’re bringing with you with as little fuss as possible? — BH

Best Earbuds for Sleep: Soundcore Sleep A10

The Soundcore Sleep A10 may look like earplugs, but they’re actually fully functional earbuds. They’re slimmer and lighter than any other in-ear headphones we’ve tried out, making them comfortable even for side-sleepers (something that anyone who’s fallen asleep wearing a pair of AirPods Pro can tell you is not always the case). The Sleep A10 feature wings so that they stay put, as well as Twin Seal ear tips that passively block noises that could wake you up—even if you sleep next to someone with a tendency to snore. They don’t have active noise canceling, but the Soundcore app comes packed with ambient soundscapes to help drown out nighttime disturbances. Our favorite feature, though, is that—unlike many of their peers—you can use these sleep earbuds to listen to your own music or podcasts via Bluetooth if that’s what you need to drift off. You can also use the app to track your sleep patterns. — BH

Best Soundbar: Sennheiser Ambeo Max

Sennheiser’s powerful virtualization technology allows the Ambeo Max soundbar to deliver room-filling audio without the need for extra surround speakers or a subwoofer. Sennheiser uses the included microphone to scan your room and calibrate output from its 13 side-, front-, and upward-firing speakers to create the best Dolby Atmos or DTS:X experience offered from a single unit. You get four HDMI (one eARC), optical, and RCA inputs, plus Bluetooth and Wi-Fi connectivity that supports AirPlay 2, Chromecast, Spotify Connect, and Tidal Connect. All that sound comes in a very tall package, so you’ll want to use the Ambeo Max with a wall-hanging television to avoid blocking the bottom of your screen. — James Barber

Best Soundbar for Home Theater: Samsung HW-Q900C

Samsung’s HW-Q900C soundbar and wireless subwoofer combo offers 7.1.2 channel Dolby Atmos True HD and DTS:X sound via its dedicated center channel and front-, side-, and up-firing speakers. Samsung supports Alexa and its own Bixby protocol for voice control, while users can play music using Bluetooth, Wi-Fi, Spotify Connect, Tidal Connect, and Airplay 2. Audiophiles can play back hi-res WAV and FLAC music files. If you also own a Samsung television that supports the company’s Q-Symphony feature, the HW-Q900C can use the TV’s speakers as part of its audio array. The SpaceFit Sound Pro functionality analyzes your living room and optimizes output to fit your space, while adaptive sound features can emphasize dialog. — JB

Best Surround Sound System: Sony HT-A9 With SW5 Subwoofer

Sony offers a remarkably immersive home theater experience with this wireless four-speaker and subwoofer system. Its 360 Spatial Sound Mapping technology uses a series of sound pulses to read your living room and create up to 12 phantom speakers. When paired with a Sony Bravia, the television speakers can act as an additional center channel. The system supports Dolby Atmos, Dolby True HD, DTS:X, and DTS Master Audio, and also does an impressive job with immersive 360 Reality Audio music tracks from services like Tidal, Amazon Music, and Deezer. Each speaker weighs just over 1.5 pounds, making the HT-A9 system one of the most easy-to-use systems available for an Atmos home theater. — JB

Best Smart Soundbar: Bose Smart Ultra

The Bose Smart Ultra soundbar supports Amazon Alexa, Chromecast, Apple AirPlay 2, Bluetooth, and Wi-Fi in an all-in-one unit that offers Dolby Atmos playback with a single connection to your television. The soundbar has nine built-in speakers and can be upgraded later with a Bose subwoofer and surround speakers. Bose has designed a noise-rejecting mic system that allows Alexa to pick up voice commands even if you’re blasting a movie at full volume. Its Voice4Video technology expands Alexa’s capabilities, allowing the user to control a television or cable/satellite box with just their voice. The Smart Ultra supports Spotify Connect, while the Bose app adds support for the Amazon Music, iHeart Radio, TuneIn, and Sirius XM streaming services. — JB

Best All-in-One Audio System: Andover-One Turntable Music System

Andover delivers outstanding audio quality in a small-footprint system that minimizes vibration, allowing a turntable to sit atop a powerful 270-degree stereo speaker array. The company uses Pro-Ject components for its turntable and a carbon-fiber tonearm along with an Ortofon 2M Silver cartridge. Two-way Bluetooth supports AAC, aptX, and aptXHD, allowing users to stream music from a phone to the speaker or stream vinyl to wireless headphones. The Andover-One, powered by a 150-watt Class D amplifier, comes with multiple analog and digital inputs to connect CD players or music streamers as well as an output for an optional subwoofer. In addition, users can add a custom stand that stores up to 100 record albums. — JB

Best All-In-One Wireless System: Naim Mu-so 2nd Generation

If living with an imposing audio system is not your style, and the music is all that matters, then take a deep breath and embrace the Mu-so 2nd Generation. Naim’s slim all-in-one system spreads a sound field whose full-range presence belies the elegant form factor that could be a miniature architectural model of a Bauhaus residence. It’s hard to believe that so much powerful sound can come from such a simple-looking—and simple-to-use—component. As the perfect complement to a hard-earned martini at 5:01 p.m., the Mu-so could become a happy habit, a sonic relaxer that brings tranquility to the end of a hectic day. — RR

Best Turntable With Arm & Cartridge: Luxman PD-191A / LMC-5 Cartridge

While a dedicated vinyl lover can easily allocate 10 times as much to a turntable, the new Luxman rig proves that excellent value and near-state-of-the-art performance can prevail without diving headlong into the vinyl abyss. The Japanese manufacturer’s most ambitious turntable spins three record speeds (33, 45, and 78 rpm) on a heavy aluminum platter. The thick aluminum plinth achieves maximum rigidity, while the motor and power supply are mounted on a rigid bottom plate to isolate the tonearm and cartridge from transmitted vibration. A sophisticated tonearm developed jointly with SAEC, one of Japan’s most respected tonearm manufacturers, uses knife-edge bearings and features an effective arm length of 10 inches to further reduces cartridge tracking error. Add the optional acrylic dustcover and Luxman’s LMC-5 moving-coil cartridge for a turnkey turntable solution. — RR

Best Retro-Modern Turntable With Arm & Cartridge: Thorens TD 124 DD 140th Anniversary / Ortofon SPU 124 140th Anniversary Cartridge

Park any new supercar next to its 50-year-old ancestor and chances are, the old-timer will command more attention than its contemporary counterpart. In the audio world, products such as the Thorens TD 124 DD are simply timeless, while delivering performance that will embarrass most brand-new turntables. The 140th Anniversary Edition adds a copper platter and other refinements, mechanical and aesthetic, to last year’s choice. It looks strikingly similar to the company’s original TD 124 made from 1957 to 1967, yet the DD differs in using a direct-drive motor rather than idler-drive design. Its tonearm appears identical, too, though is much improved, as is the available Ortofon SPU moving-coil cartridge that brings so much life—with force and impact—to LP playback. — RR

Best Bang-for-the-Buck Turntable: Technics SL-1200GR2

Anybody old enough to remember when the Rolling Stones’s Exile on Main Street was new in 1972 may remember that the original Technics SL-1200 came out a few months later. Both album and turntable were all the rage, and the Technics was the first quality direct-drive turntable that a penurious college student could afford. It went on to become a favorite of DJs, and now, the SL-1200GR2 brings a familiar look to a vastly improved design, recently updated as the GR2. Its rock-solid speed accuracy, robust chassis, and sophisticated S-shaped magnesium tonearm make the 21st century SL a no-brainer for LP lovers on a budget. — RR

Best Home Theater Receiver: McIntosh MHT300 Home Theater Receiver

Last year’s pick of the McIntosh MX123 processor and MC257 multi-channel amp are still great choices for movie and surround-sound systems with the space and budget to let the dinosaurs roam. Less capacious entertainment venues will appreciate an all-in-one component like the MHT300 Receiver. Featuring 7.2 channels (expandable to 7.2.4), it delivers 150 wpc into four ohms and 120 wpc into eight ohms with all seven channels driven. That means every loudspeaker gets enough juice to make explosions, machine-gun fire, and screaming psycho-killers come to life in the comfort of a condominium. Dirac Live Room Correction and near-infinite connectivity allow users to fine-tune the sound from multiple sources. And when it’s time for something less stimulating, users will enjoy the built-in FM tuner for enjoying free, over-the-air radio broadcasts. — RR

Best Solid-State Integrated Amplifier: Dan D’Agostino Master Audio Systems Momentum MxV Integrated Amplifier

Recognized as among the finest audio electronics on the planet, a full-house D’Agostino system driving equivalent loudspeakers can easily crash through the $2 million barrier. And yet, the Momentum MxV Integrated Amplifier harnesses the essence of D’Agostino’s Relentless and Momentum Series in a single-chassis component that delivers 250 wpc with a full-function line stage, one whose sound is every bit as detailed, seductive, and musical as the Momentum separates. When it’s equipped with the optional phono stage and digital streaming modules, one need only add top-tier speakers and a turntable to build a minimalist, state-of-the-art digital and analog system that, while not inexpensive, could be regarded a bargain for those seeking the very best. — RR

Best Vacuum Tube Integrated Amplifier: Western Electric 91E

As we said last year, extolling the sonic virtues of the 300B vacuum tube to someone unfamiliar with this amplification device is like explaining how a truffle is unlike any common mushroom. Just as that precious fungus is a gustatory revelation, an amplifier using the 300B offers a rich, multi-layered audio experience with sound as seductive as it is addictive. Western Electric invented the 300B in 1938, and the company, resurrected in 1996, soon began to remanufacture the legendary tube. The Western Electric 91E integrated amplifier is a SET (single-ended triode) design that delivers double the power of traditional 300B amps and makes any but the most power-hungry loudspeakers sing to the heavens. The component’s exquisitely machined chassis reminds us that audio gear can be jewelry, too. Until someone does it better, this is the integrated tube alter of choice. — RR

Best Bang-for-the-Buck Integrated Amplifier: Moon River 404 Reference Integrated Amplifier

Moon River Audio was introduced to Robb Report readers in the October 2022 issue, and now the 404 Reference cements this Swedish manufacturer’s claim to building the best integrated amplifier for the price. Distinguishing the Reference from the 404 Standard are its vastly improved power supply—doubled in capacitance—and the unit’s ability to drive virtually any loudspeaker with its relatively modest 50 wpc, proof once again that specifications don’t tell the whole story. Features like a tape monitor loop, stereo/mono switch, and a versatile MM/MC phono module offer added “army-knife” functionality. Like good Scandinavian furniture, the Moon River’s classic, understated design will endear it to those who like to look at, as well as listen to, a fine component. — RR

Best Solid State One-Brand Separates: Mola Mola Makua Preamplifier / Lupe Phono Stage / Perca Stereo Amplifier / Tambaqui DAC

Made in the Netherlands and named after one of the ocean’s most unusual fish, Mola Mola has been building class-defining solid-state gear since 2011. The handiwork of famous designer Bruno Putzeys, Mola Mola’s take-no-prisoners approach to sound has earned the company accolades in the audio press. Similarly, the build quality of these dramatically shaped, half-sized-chassis components rivals the very best at any price. The amplifiers, with no sonic signature of their own, use Putzeys’s Class D NCORE technology, while particularly notable are the Tambaqui DAC and Lupe Phono Stage, antipodal sources that aim at—and hit—the same perfectionist mark. — RR

Best Vacuum Tube One-Brand Separates: Linear Tube Audio Microzotl Preamplifier / Ultralinear+ Amplifier / Aero DAC

Audio gear using vacuum-tubes continues to attract acolytes in much the same way that an LP spun on a turntable can seem more alive, fleshed out, simply real . LTA tube-based gear is clean and clear, plus it sounds as if a veil has been removed, preserving only the nature of music itself. That’s because physicist David Berning, who invented ZOTL (Zero hysteresis Output Transformer-Less) tube architecture in 1996, eliminated audio output transformers because of the restrictions they impose on amplifier performance. This topology allows LTA amplifiers to have a flat frequency response from eight hz to 50 Khz, nearly impossible with an output transformer. Relatively efficient loudspeakers of will sing like never before in a system whose design aesthetic is as beautifully minimal as its performance is overwhelmingly impressive. — RR

Best Digital Music Server/Streamer/DAC: Aurender A20

In the computer Stone Age, it was often said that “Nobody ever got fired for buying IBM.” And today, a sure audiophile decision is choosing Aurender as one’s digital streaming component. Throw in a world-class DAC and you have the A20, Aurender’s all-in-one digital source that has made many a music lover jettison their CDs and LPs. Whether one calls it the lazy person’s way of reaching musical nirvana, or just a “smarter source,” the Aurender’s tank-like build and impeccable sound quality put it into digital’s top-tier, enhanced by a user interface that is intuitive and reliable. Music collectors with large CD libraries will want the A30 ($19,999), which rips your CD collection and has 10 TB of internal hard-drive storage. — RR

Best Audiophile Cables: RSX Technologies Benchmark Series

For thoughtful music listeners with open minds and sufficiently resolving systems, good cables do indeed make an audible sonic improvement. One needn’t spend the price of a Mercedes-Benz E-Class to get there, either. Sanity prevails with RSX Technologies’ Benchmark Series cables, which provide a stem-to-stern solution for every component in the system. Designed by cable-industry veteran Roger Skoff of XLO Cables fame, the Benchmark series includes ER-11 Line Level, ER-31 Phono, and ER-41 Digital Interconnects in various lengths and terminations. The ER-61 Speaker Cables use flexible, 11+AWG Litz-variant geometry solid copper conductors terminated with gold-plated banana plugs. Many audiophiles contend that a component’s power cord—especially for the amplifier—is the most important cable connection of all, and the ER-20 Power Cord, at just $200, delivers audible improvement well beyond its modest price. — RR

Best Audio Racks: Solidsteel HY Series

Finding just the right support for audio components is a challenge. The best can be as costly as the gear itself, while inexpensive racks don’t usually provide the sturdy structure, stability, and vibration isolation needed, especially when stacking three or four shelves high. Solidsteel is an Italian brand whose racks have stood the test of time, not just with their practical performance but with aesthetics befitting the best gear placed atop their thick shelves. Machined steel legs and damped shelves in black, wood or even marble complement any environment, and allow users the freedom to adjust height based on clever extensions to individual legs. The HY (Hyperspike) Series hits a sweet spot.

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Hemingways Watamu: fall asleep to the sound of the ocean in Kenya's Marine National Park

S ynonymous with safari and the big five, Kenya ’s coast often mistakenly gets overlooked in favour of the country’s impressive game reserves. But with swathes of white sands and an ocean that teems with wild spinner dolphins, humpback whales, and vividly coloured fish, this is one part of the world you don’t want to miss out on.

Unfolding directly onto the paradisiacal beachfront, and surrounded by swaying palms, manicured gardens dotted with bird of paradise blooms, and a handful of swimming pools that mirror the cloudless, bright blue expanse of sky above, Hemingways Watamu embraces frazzled guests like long-lost friends.

But it’s not only the surroundings that add to the magic, it’s the people who work here that make this five-star resort feel like a true home away from home. Always eager to chat, Hemingways’ hardworking staff elevate this hotel from amazing to truly exceptional.

As the jumping-off point for one of Kenya’s first protected marine parks, and recognised as a UNESCO Biosphere Reserve due to its abundance of coral gardens, and impressive marine life, the village of Watamu - where Hemingways is located - is a truly unbeatable natural haven.

The closest airport to the hotel is 30 minutes away in the town of Malindi, a one-hour, 15-minute plane ride from Kenya’s capital Nairobi. Otherwise, it’s around a two-hour drive from Mombasa along an epic coastal road where the ocean changes colour by the second, from cobalt blue, and azure to the brightest turquoise. Direct flights from London to Nairobi are available daily, starting at around £600 return with BA.

With a fresh colour palette of bright whites, soft blues, and sage greens, the hotel has been designed to allow the natural beauty of the surroundings to truly shine. The huge open restaurant area that affords breathtaking views of the ocean from almost every angle stands out as the focal point of the complex. Here wicker tables and chairs are dressed with botanical print cushions, fresh flowers, and nods to the ocean with shell and coral-inspired artworks.

The bar, on the other hand, with its free and easy atmosphere, feels slightly more rustic with wooden detailing and a focus on deep-sea fishing since life-size cast models of marlin and hammerheads proudly line the walls. It reminds me of establishments I’ve visited in Key West and Havana, places that the hotel’s namesake, Ernest Hemingway also frequented. I can almost imagine the intoxicated writer, strong cocktail in hand watching over the place at sunset.

A handful of pristine swimming pools and the serene spa cater to holidaymakers who simply want to fly and flop, while the huge on-site tennis court and well-equipped gym are ideal for fitting in a holiday run or workout.

Which room?

Hemingways Watamu boasts 76 rooms, all with an ocean view and in categories spanning deluxe singles, to two-bed apartments. For a vacation that truly wows, the Residence suites are the way to go. Residence number eight is one of the most impressive, featuring a spacious ensuite double room complete with a four-poster canopied bed, a separate twin bedroom with its own en-suite and large bathtub, an expansive open-plan dining-living-kitchen area that’s bigger than most London apartments, and a private wrap-around terrace with daybed and loungers.

Two comfy full-size sofas, a circular wooden dining table, work desk, and a full kitchen ensure guests can comfortably reside at Hemingways for months on end should they desire. There’s even a sizeable walk-in wardrobe. Decor is tastefully simple, without too much fuss and fanfare, like the rest of the hotel, it’s the views here that command all the attention.

Food & drink

Buffet dining can occasionally equate to poor quality or bland dishes, but that’s not the case at Hemingways. Breakfast options feature an abundance of delightful options with fresh fruit juices, tart passion fruits, locally grown melons and pancakes being the highlights. But there’s everything you can imagine, from eggs and crispy bacon to waffles and pastries and plenty of incredible Kenyan tea and coffee — all served overlooking the Indian Ocean.

Buffet dining is also available each evening or there’s the option to order from the a la carte menu where seafood is the standout option. Native grilled rock lobster slathered in butter, fresh shrimp with chilli and garlic, and any of the house specials — black pepper kingfish, Swahili coconut chicken, and fish creole — all impress.

Since the coastal area around Watamu has a strong Italian community that dates back to around the 1960s it’s not unusual to find good gelato and pasta in town. Nearby Papa Remo serves plates of authentic Italian dishes with sublime service.

Extracurricular

While it would be easy to relax for a week at Hemingways it would be a shame not to visit the coral gardens that bustle with wildly elegant marine life like parrotfish, sweetlips, lionfish, and snappers. The hotel can arrange boat excursions that leave directly from the beach in front of the hotel, so guests can spend a few hours snorkelling, wild dolphin spotting, or even getting up close to humpback whales, which can be seen for around four months each year, from June onwards.

Eco World Watamu, just a short drive away from the hotel, is a community-run project that collects plastic waste to sort and recycle. Partnering with local women and youth groups the organisation promotes awareness around recycling and beach clean-ups. Tours of the centre are available to book through the hotel and provide an inspiring overview and the chance to pick up a recycled trinket.

Still hankering after the big five? It’s possible to witness elephants who will occasionally visit Arabuko Sokoke Swamp’s watering holes just before sunset. Then board a majestic single-sailed dhow for a sunset cruise along Mida Creek, with a glass of wine in hand, it’s the ideal way to wrap up a day in paradise.

Best for...

Daydreamers, nature lovers, couples, friends, or families — this place really does cater to all. With direct beachfront access, endless activities, welcoming staff, and fresh home-cooked seafood, Hemingways Watamu is the ideal tropical holiday destination or the perfect location for a post- safari wind-down.

Double rooms available from £437 on a half-board basis, hemingways-collection.com

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Red Cross to visit homes in Central Maui, install free smoke alarms this Saturday

This Saturday, March 23, the American Red Cross and community partners will participate in events across the state to promote home fire safety and install free smoke alarms as part of the national “Sound the Alarm” campaign.

The Red Cross will conduct neighborhood visits for local families in Central Maui on Saturday, March 23 from 9 a.m. to noon. To sign up for a home visit from the Red Cross for fire safety and response education and to install a free smoke alarm, visit  www.soundthealarm.org .

Sounding the Alarm in Hawaiʻi

According to Red Cross Hawaiʻi, the most common disaster the Red Cross responds to is home fires. The Sound the Alarm campaign is a proactive effort to lessen the number of families impacted by this form of disaster.

With each home visit, volunteers will work with residents to formulate escape plans, watch for potential fire hazards and install new smoke alarms.

Sound the Alarm Events

Several events will be featured for home visits across the islands.

• Central Maui neighborhood visits from 9 a.m. to noon
• Papakōlea Hawaiian Homestead from 9 a.m. to 1 p.m.
• Waikīkī Townhouse from 9 a.m. to 1 p.m.

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Macdonald Bear Hotel

Oxfordshire, ox20 1sz

This beautiful hotel was formerly a 13th century coaching inn, you will find The Bear at the centre of the market town of Woodstock, just a 15 minute drive from Kirtlington Park. The hotel is full of period features, oak beams and rich interiors, it’s a hidden gem where the combination of history, culture and exceptional facilities make it one the finest 4-star hotels in Oxfordshire. The hotel is a really lovely choice for a weekend break.

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The Latest | Netanyahu cancels diplomats' visit to Washington in protest over U.N. vote

Israel Palestinians Parachutes carrying humanitarian aid dropped from aircraft into Beit Hanoun, northern Gaza Strip, seen from southern Israel, Monday, March 25, 2024. (AP Photo/Maya Alleruzzo) (Maya Alleruzzo/AP)

Israeli Prime Minister Benjamin Netanyahu has canceled a planned visit to Washington by a high-level delegation to protest Monday’s U.N. Security Council decision calling for an immediate cease-fire in Gaza.

The resolution passed 14-0 on Monday after the U.S. decided not to use its veto power and instead abstained. The U.S. has previously vetoed three resolutions demanding a cease-fire.

The resolution also calls for the release of all hostages taken captive during Hamas’ Oct. 7 surprise attack in southern Israel. But the measure does not link that demand to its call for a cease-fire, intended for the ongoing Muslim holy month of Ramadan, which ends April 9.

International aid officials say the entire population of the Gaza Strip — 2.3 million people — is suffering from food insecurity and that famine is imminent in the hard-hit north.

More than 32,000 people have been killed in the territory, and more than 74,000 wounded, according to Gaza's Health Ministry, which doesn't differentiate between civilians and combatants in its counts. It says women and children make up two-thirds of the dead.

Some 1,200 people were killed on Oct. 7 when Palestinian militants launched a surprise attack out of Gaza, triggering the war, and abducted another 250 people. Hamas is still believed to be holding some 100 Israelis hostage, as well as the remains of 30 others.

— Palestinians describe bodies and ambulances crushed in Israel's ongoing raid at Gaza's main hospital

— UN to vote on resolution demanding a cease-fire in Gaza during current Muslim holy month of Ramadan

— Thousands of Christians attend Palm Sunday celebrations in Jerusalem against a backdrop of war

— Israeli airstrike in northeastern Lebanon wounds 3, local official says

— Find more of AP's coverage at https://apnews.com/hub/israel-hamas-war .

Here's the latest:

JERUSALEM -- Israeli Prime Minister Benjamin Netanyahu has canceled a planned visit to Washington by a high-level delegation to protest Monday’s U.N. Security Council decision calling for an immediate cease-fire.

The resolution passed 14-0 on Monday after the U.S. decided not to use its veto power and instead abstained.

Netanyahu accused the U.S. of “retreating” from what he said had been a “principled position” by allowing the vote to pass without conditioning the cease-fire on the release of hostages held by Hamas.

The Israeli delegation was to present White House officials with plans for an expected ground invasion of the strategic Gaza town of Rafah, where over 1 million Palestinian civilians have sought shelter from the war.

UNITED NATIONS — The United Nations Security Council has demanded a cease-fire in Gaza during the Muslim holy month of Ramadan, its first demand to halt fighting.

The United States abstained on the resolution, which also demanded the release of all hostages taken captive during Hamas’ Oct. 7 surprise attack in southern Israel.

However, the measure does not link that demand to the cease-fire during the Muslim holy month of Ramadan, which ends April 9. Because Ramadan ends next month, the cease-fire demand would last for just two weeks, although the draft says the pause in fighting should lead “to a permanent sustainable cease-fire.”

Since the start of the war, the Security Council has adopted two resolutions on the worsening humanitarian situation in Gaza, but none has called for a cease-fire.

The United States has previously vetoed three resolutions demanding a cease-fire in Gaza, the most recent an Arab-backed measure on Feb. 20. That resolution was supported by 13 council members with one abstention, reflecting the overwhelming support for a cease-fire.

Russia and China vetoed a U.S.-sponsored resolution in late October calling for pauses in the fighting to deliver aid, the protection of civilians and a halt to arming Hamas. They said it did not reflect global calls for a cease-fire.

They again vetoed the U.S. resolution Friday, calling it ambiguous and saying it was not the direct demand to end the fighting that much of the world seeks.

CAIRO -- Hamas has accused the United States on Monday of disrupting cease-fire talks the militant group has been holding with the Israeli government.

In a statement, Hamas said the U.S. should not be a mediator due to its support of Israel.

“The American administration is the main reason for stalling any agreement,” senior Hamas official Husam Badran said in a statement. He also described Washington as “military partner” of Israel, making it unfit to play the role of mediator.

The criticism comes days after a fresh round of cease-fire talks concluded in Doha, Qatar, which included the CIA chief, William Burns.

The U.S. has provided Israel with key diplomatic and military support throughout the war. It has worked with Qatar and Egypt in mediation attempts to broker a deal that would include a pause in fighting and the release of Israeli hostages held by Hamas.

Hamas has demanded guarantees for an end to the war, the release of Palestinian prisoners and a plan for reconstruction of war-battered Gaza.

During a previous one-week cease-fire in November, around 100 hostages, mostly Israelis, were released in exchange for 180 Palestinian prisoners.

Badran also claimed that Israeli Prime Minister Benjamin Netanyahu is not interested in a deal and is deceiving hostages’ families.

Israeli media have reported that Israel has accepted a formula that would release hundreds of prisoners for the hostages and was waiting for a response from Hamas.

“The issue is not related to the prisoners and their numbers,” Badran said. “The problem is that the occupation refuses to give any guarantees to the mediators on the basic issues in the lives of people in Gaza.”

Netanyahu has repeatedly accused Hamas of making unrealistic demands.

AMMAN, Jordan — The U.N. secretary-general says there is a “growing consensus” that an Israeli ground invasion of the southern Gaza city of Rafah would be a “catastrophic humanitarian disaster."

António Guterres, speaking to reporters during a visit to a Palestinian refugee camp in Jordan on Monday, reiterated his call for a cease-fire and the release of all hostages held by Hamas.

He noted that the United States, European and Muslim countries have urged Israel not to expand its ground offensive to Rafah.

Some 1.4 million Palestinians, most of whom have fled fighting elsewhere in Gaza, have packed into the southern city on the border with Egypt. Israel and Egypt refuse to accept refugees, and it's unclear where civilians could flee within the war-ravaged territory.

Israel says Hamas maintains four battalions with thousands of fighters in Rafah, and that it cannot defeat the militant group without crushing them.

“I strongly hope that this consensus that is emerging in the whole of the international community will make Israel reflect and avoid what would be a dramatic threshold,” Guterres said.

JERUSALEM -- Tens of thousands of Israelis are celebrating the Purim holiday in Jerusalem in the shadow of the war in Gaza.

The festival of Purim marks the victory of Jews over a tyrant in ancient Persia and is celebrated with costumes, drinking and parties.

Although many cities across Israel decided to cancel the celebrations due to the ongoing war, Jerusalem — celebrates Purim one day later than the rest of the country — held a traditional Purim parade for the first time in 42 years. It featured large floats of beloved children’s characters and DJs dressed up as characters from the story of Purim.

About two dozen family members and supporters of the approximately 100 hostages being held in Gaza protested the parade.

“I know it’s tradition to be happy on Purim, but this year I think it’s tactless to do these carnivals,” said David Heyd.

Other family members of the hostages kicked off the parade, marching silently at the front with a giant yellow ribbon.

“My daughter, she needs to be here, she was supposed to be here. I am wearing a shirt she was supposed to wear, and I’m waiting for her,” said Meirav Leshem Gonen, whose daughter Romi has been held hostage in Gaza for 170 days.

As the parade wound its way through the streets of Jerusalem, children in colorful costumes packed the streets eating sweets and cookies, waiting for the floats to pass.

“We’re showing the whole world and our enemies that we’re continuing to live, continuing to celebrate,” said Shabi Levy, a Jerusalem resident who was watching the parade with his three children.

RAFAH, Gaza Strip — Palestinian health officials say Israeli strikes have killed at least 30 Palestinians in the southern city of Rafah over the past 24 hours.

The Abu Youssef al-Najjar Hospital, which received the bodies, said Monday that 10 children and 11 women were among those killed.

Israel has vowed to expand its ground offensive to Rafah, which is now housing some 1.4 million people – more than half of Gaza’s population. Most have fled fighting elsewhere.

Israel ordered Palestinians to move south in the opening months of the war but has continued to carry out strikes in all parts of the territory, including Rafah.

The United States, Israel's closest ally, has urged Israel against launching a major operation in Rafah, warning of a humanitarian catastrophe. Israel says it cannot defeat Hamas without going into Rafah , where it says the group has four battalions composed of thousands of fighters.

Israel’s offensive has killed over 32,000 Palestinians, according to local health officials, and driven a third of Gaza’s population to the brink of starvation. It was launched in response to Hamas’ Oct. 7 attack into Israel, which killed some 1,200 people, mostly civilians.

Hamas-led militants also took around 250 people hostage. It is still holding around 100 hostages, and the remains of around 30 others, after most of the rest were freed during a cease-fire last year in exchange for the release of Palestinian prisoners.

DEIR AL-BALAH, Gaza Strip — Palestinian health officials say an Israeli airstrike on an apartment block in central Gaza killed at least 21 Palestinians from two extended families.

The strike late Sunday killed 10 members of the Salman family and 11 members of the Buhesi family, according to hospital records. An Associated Press reporter saw the bodies at the hospital in the central town of Deir al-Balah.

The Israeli military says it tries to avoid harming civilians and blames civilian casualties on Hamas because the militants fight in dense, residential neighborhoods. But the military rarely comments on individual strikes, which often kill women and children.

The war broke out on Oct. 7. when militants from Gaza stormed into southern Israel, killing at least 1,200 people, mostly civilians, and taking another 250 hostage.

In response, Israel launched one of the deadliest and most destructive military campaigns in recent history. Gaza's Health Ministry says over 32,000 Palestinians have been killed. It does not differentiate between civilian and combatant casualties but says women and children make up around two-thirds of those killed.

RAFAH, Gaza Strip — Aid groups that visited a packed Gaza hospital described an “unimaginable” situation in which large open wounds were left untreated.

An emergency medical team organized by three aid groups spent two weeks carrying out surgeries and other care at the European Gaza Hospital near Khan Younis. The southern city has seen heavy fighting between Israeli forces and Palestinian militants since the start of the year.

The hospital has expanded to 1,000 beds from its original capacity of 200 to accommodate patients from Nasser Hospital, the main hospital in Khan Younis, which Israeli forces raided last month . There are also an estimated 22,000 people sheltering at the European Gaza Hospital.

The visiting surgeons “reported large infected open wounds on patients and having to administer emergency nutritional supplies to patients as the lack of food was jeopardizing patient treatment.”

In a statement released Monday, the team said healthcare workers had been forced to evacuate or were unable to access the hospital. It said Israeli restrictions had led to shortages of medical supplies, including basics like gauze and plates and screws used to stabilize broken bones.

Israel accuses Hamas of using hospitals and other civilian facilities to shield its fighters and has raided a number of medical facilities since the start of the war. Most of Gaza’s hospitals have been forced to shut down, even as scores are killed and wounded each day in Israeli strikes.

Israel’s offensive has killed over 32,000 Palestinians, and experts warn that even more are at risk of dying from disease and starvation.

The war began on Oct. 7, when Hamas-led militants stormed into Israel and killed some 1,200 people, mostly civilians, and abducted around 250 people.

The emergency medical team was organized by Medical Aid for Palestinians, the International Rescue Committee and the Palestine Children’s Relief Fund.

UNITED NATIONS — The U.N. Security Council is set to vote Monday on a resolution demanding an immediate humanitarian cease-fire in Gaza during the Muslim holy month of Ramadan .

The vote comes after Russia and China vetoed a U.S.-sponsored resolution Friday that would have supported “an immediate and sustained cease-fire” in the Israeli-Hamas conflict.

The United States warned that the resolution to be voted on Monday morning could hurt negotiations to halt hostilities by the U.S., Egypt and Qatar, raising the possibility of another veto, this time by the Americans.

The resolution, put forward by the 10 elected council members, is backed by Russia and China and the 22-nation Arab Group at the United Nations.

JERUSALEM — Thousands of Christian faithful attended Palm Sunday celebrations at Jerusalem’s sacred Mount of Olives, marking the first day of Holy Week as conflict surges across the region.

Pilgrims waved branches and fronds in the air, items that were placed before Jesus’ feet as he was greeted by cheering crowds during his entrance into Jerusalem, according to the Bible. Earlier Sunday, Jerusalem’s Church of the Holy Sepulchre — revered as the site of Jesus’s crucifixion — also held a service.

The annual celebration came as the Israel-Hamas war rages on in Gaza. However, the conflict appeared to have had little effect on the procession, which swelled to a similar size as last year.

The celebration marks the beginning of the most somber week in the Christian calendar, which marks Jesus’ crucifixion on Good Friday and his resurrection on Easter.

BEIRUT — An Israeli airstrike deep in northeastern Lebanon early Sunday wounded at least three people, a local official said.

The airstrike near the city of Baalbek, a stronghold of Lebanon’s militant Hezbollah group, was the latest to hit the area in recent weeks.

The strike occurred a few minutes after midnight and wounded three people according to Baalbek’s mayor, Bachir Khodr, who posted the news on X.

It was not immediately clear what was struck. The strike came hours after Hezbollah said it used two drones carrying explosives to attack an Israeli Iron Dome missile defense system in the northern Israeli town of Kfar Blum.

The Israeli military said warplanes attacked a workshop used by Hezbollah for military activities. It added that after the strike some 50 rockets were fired from Lebanon toward Israel, saying some were shot down and others fell in open areas.

Copyright 2024 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed without permission.

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Justice Department Launches the National Extreme Risk Protection Order Resource Center

The Justice Department launched the National Extreme Risk Protection Order (ERPO) Resource Center (the Center) which  will provide training and technical assistance to law enforcement officials, prosecutors, attorneys, judges, clinicians, victim service and social service providers, community organizations, and behavioral health professionals responsible for implementing laws designed to keep guns out of the hands of people who pose a threat to themselves or others.

“The launch of the National Extreme Risk Protection Order Resource Center will provide our partners across the country with valuable resources to keep firearms out of the hands of individuals who pose a threat to themselves or others,” said Attorney General Merrick B. Garland. “The establishment of the Center is the latest example of the Justice Department’s work to use every tool provided by the landmark Bipartisan Safer Communities Act to protect communities from gun violence.”

ERPO laws, which are modeled off domestic violence protection orders, create a civil process allowing law enforcement, family members (in most states), and medical professionals or other groups (in some states) to petition a court to temporarily prohibit someone at risk of harming themselves or others from purchasing and possessing firearms for the duration of the order.

In 2023, the Justice Department’s Office of Justice Programs (OJP) awarded $238 million to states, territories, and the District of Columbia under the Byrne State Crisis Intervention Program (SCIP), which was created by the Bipartisan Safer Communities Act and is designed to help jurisdictions implement crisis intervention strategies, including ERPO programs. In addition, OJP awarded $4 million to support training and technical assistance under Byrne SCIP, including $2 million that was awarded to the Johns Hopkins Center for Gun Violence Solutions to establish the ERPO Resource Center. In collaboration with OJP’s Bureau of Justice Assistance (BJA), the Center will support states, local governments, law enforcement, prosecutors, attorneys, judges, clinicians, victim service providers, and behavioral health and other social service providers in their efforts to implement ERPO programs to fit local needs, share resources and promising practices with the field, and help ensure that funding received through Byrne SCIP is effectively utilized.

“Supporting our law enforcement and community partners in curbing the scourge of gun violence is more critical than ever,” said Acting Associate Attorney General Benjamin C. Mizer. “In addition to other resources leveraged across the Justice Department, this Center will provide communities with new tools and technical assistance to help them implement effective crisis intervention strategies and reduce gun violence.”

“OJP’s investment in ERPO programs demonstrates the Department’s commitment to addressing the gun violence crisis in the United States,” said OJP Assistant Attorney General Amy L. Solomon. “This crisis cannot be solved at one level of government. We must use all of our resources and collaborate at the federal, state, and local levels to find innovative, evidence-based, and holistic solutions to help keep American communities safe.”

Through the Center and its newly launched website , states, local governments, law enforcement, prosecutors, attorneys, judges, clinicians, victim service providers, and behavioral health and other social service providers will have direct access to critical information that will enhance their ability to reduce firearm homicides and suicides. The website will be maintained and updated to include newly developed resources for the field created through the Center, in partnership with BJA. The website also provides a platform for the Center to highlight emerging and promising practices in successful ERPO implementation and connect states and localities to innovative strategies to reduce gun violence and save lives.

As of this month, 21 states and the District of Columbia have enacted ERPO laws. Successful and effective ERPO implementation requires a comprehensive and holistic approach that incorporates a wide range of stakeholders. The Center is designed to provide resources consistent with that need.

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