Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. Applications of acoustics are for instance the audio and noise control industries.

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Nonlinear waves and shock formation

In the cases of nonlinear acoustics, why is shock formation unlikely when the dispersion is strong when compared to the nonlinearity of the wave?
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What is the meaning of “frequency of a human voice”?

The term frequency for a periodic wave can be defined as the number of times a repeating pattern occurs in a given time period (eg: no. of crest and trough cycles per second for EM wave). But what ...
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461 views

Resonance Experiment

Today in high school physics class, we performed an experiment on the resonance of sound, with a set up like this... To put it simply, the sound waves are supposed to rebound with the surface of ...
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Can a sound like a sonic boom change a object like a wall? And how the light on the walls will be changed after a sound like this? [closed]

Can a sound like a sonic boom change a object like a wall? And how the light on the walls will be changed after a sound like this?
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48 views

Modeling Acoustic Lubrication

I thought about posting this question in the Biology StackExchange site but really it is just the application of my question that applies to biology not the core of the question itself. Can anyone ...
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1answer
39 views

How could you minimize sonic boom at the ground level?

I've heard that one of the reasons that we don't have commercial supersonic flight is because of the sonic boom produced. Is this really a deal-breaker and if not, how do you get around/minimize the ...
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394 views

Open pipe resonance

I read somewhere, a closed pipe has resonance with a sound of wave length 4 times the length of pipe (from open end to closed end), when putting a source above the open end (since it reinforces the ...
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127 views

'Push' in a rigid rod travel at speed of sound or speed of light [duplicate]

Two person, $A$ and $B$, each holding one end of a long solid rod. Now person $A$ pushes the rod on one end. Question: Is it correct that the information that the rod has been pushed will travel ...
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421 views

Why do you only hear high frequencies when a microphone is near its speaker?

The phenomenon I'm talking about is positive feedback, as known from control engineering: when the microphone is too close to its speaker, it can "hear itself", so the signal will be infinitely ...
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Why does a glass breaks when subject to very sharp sound like in opera?

I have seen in Ripleys believe it or not that an opera singer generates a very high frequency of sound and breaks a glass window.How do they do it?
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147 views

Why is there a sharp cracking sound when we break a plastic ruler?

Why is there a sharp cracking sound when we break a plastic ruler? The question appears to be simple and common but I need a apropriate answer.
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339 views

Heating coffee by yelling?

Is it a myth that yelling to a coffee mug will heat it? I have been hearing my friend saying that screaming will heat coffee or water.
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207 views

Relative velocity of sound

Relative velocity of sound. As I know that speed of sound in medium is property of medium. And independent of source motion but depend on motion of audience or observer and motion of medium. But it ...
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136 views

Do asteroids create sonic boom while entering the atmosphere?

Because of the lack of any materials to propagate sound, it can't spread in space. There's the air in the atmosphere, but its volume mass increases constantly (either linear or exponential, I don't ...
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386 views

Measuring speed of a vehicle

I'm very primitive with my thought. So please help if you can in layman terms with an answer to this question. Here we go- by using a street power pole as the source responder, is it possible to read ...
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379 views

How small can you be and still hear?

According to my understanding, at the smallest level sound is just a collection of particles colliding on a wave. So, assuming we can arbitrarily reduce the size of any human being, how small can we ...
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1answer
203 views

Steel rod to Mars vs the speed of sound, how is supersonic travel possible?

I remember reading this passage in the "Feynman Lectures", where Dr. Feynman describes an experiment in which a theoretical metal rod of length equal to the distance between Mars and Earth is arranged ...
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533 views

FFT distortion, harmonics (singing wine glass)

I'm doing a school assignment on Singing Wine glasses (you rub the rim of the wine glass with a wet finger and it produces a pure tone). I have recorded $30\,\text{ms}$ of the "singing" at a sampling ...
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524 views

How do human ears distinguish the frequencies in sound?

If they do a Fourier transform, how can they know the formula to find coefficients?
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99 views

Impact Force versus Non-impact force why are they so different?

A mass that has velocity and a force f1, can create a sound and even break a wall upon impact. However if the same force f1 is applied to the wall without any motion (velocity) then the wall will not ...
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197 views

Is sound relative?

Is sound relative? For example, if I and my friend are having a ride at 1000 mph and I shout towards him (speed of sound 700 mph). What would happen? Will the speed of the sound relative to the ...
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51 views

Harmonics of an infinite cylinder

If a hypothetical cylinder was infinitely long, could it vibrate at any frequency, since any frequency would be a harmonic of it? And (less hypothetically) if a cylinder was only really long, would it ...
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1k views

What part of the fan blade actually does the noise generation?

I'm trying to identify the sources of noise in spinning fan blades and what causes them. Is the noise only generated by the lead edge of the blade 'cutting through' air? and different parts of it ...
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1answer
128 views

How can I validate a numerical model using an analytical solution of the same scenario?

In the course of my research project I have been tasked with validating an acoustic model, however I am having trouble conceptualising what I am supposed to do. I have found an analytical solution for ...
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126 views

physical difference between A and B

We all know that when we say A it sounds different than when we say B. I was wondering what exactly can be the difference between saying A and B in terms of physics. I first thought that it may due ...
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is it possible to load a transversal wave with a longitudinal wave

like in communication engineering for sending information what we do, we take a high frequency carrier and modulate it with the message signal so can we do the same thing like take a high ...
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121 views

Sound Propagation using Finite-Difference Time-Domain (FDTD) considering wind effects

I am trying to plot the propagation of sound from a fixed source in a 2D environment using Finite-Difference Time-Domain (FDTD) Method taking into account the effects of the wind velocity. I came ...
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Is a sonic boom a one-time bang or a continuous noise?

Is a sonic boom a one-time bang, caused when an object initially goes supersonic, or is it a continuous noise emitted by the object as it's travelling? To be more specific, will an aircraft which is ...
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59 views

Relationship between tones made by a piano

If a piano were to be tuned perfectly with the equal temperament system, what would be the relationship between standing waves from one note to the next? How would the frequency and wavelength of ...
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68 views

Energy in a wind instrument?

My physics teacher said that he saw a guy playing a very large wind instrument on TV, and the guy apparently calculated that the total energy present in the instrument when he was playing was almost ...
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206 views

Decibel equation, dyne or Watt

I know decibel is used as a ratio between two physical quantities with the same units on a logaritmic scale. Is also used for calculate the intensity of a sound, but I found it reported in two ...
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313 views

Ringing sound when you flip a coin?

When you flip a coin, you hear a ringing sound. I know that the source of the sound is the thumbnail hitting the coin, but it seems to be filtered by the spinning of the coin. Specifically, the faster ...
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436 views

Thermal Penetration Depth discrepancy

I've been working on a project that involves thermoacoustics, and one of the commonly-used values in this field is know as the thermal penetration depth. It is calculated as follows: $$\delta_k = ...
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1k views

Why do higher pitches appear to be louder?

It may just be in a few cases, but in the case of a flute, a higher pitch appears to come with a perceived higher volume. Is this simply because you need to put more energy into the flute to get a ...
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148 views

High frequency sound transmission through plastic. I can't hear enough treble! [closed]

I have a large cylinder made of a rigid thick plastic with a speaker inside of it. I want to be able to hear high pitched / high frequency noise from the outside but I'm primarily hearing bass. The ...
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Bass and Treble-Car Steroes

In a car which phenomenon, diffraction or the resonant frequency of the car, lends itself more to the ability of bass to go farther? Related Answer: Why do bass tones travel through walls?
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Varying the amplitude of a driven wave

I' d like to know whether varying the amplitude of a system at resonance is possible or not and if it is, how? I've calculated the resonance frequency of a material and I'd like to know the ...
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A Doppler Effect problem with a moving medium

I tried solving the following question and started having multiple doubts: Two cars A and B are moving towards each other with some speed $25$ m/s. Wind is blowing with speed $5$ m/s in the ...
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1answer
111 views

Hearing sound around corners

I've been taught that diffraction is the reason why we can hear around corners, since the wavelength of sound is approximately 10 cm (smaller than a door or a window). I wonder how can this be ...
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A Musical Pathway

Using a small number of sound emitters, could you create a room where certain nodes emitted particular tones, but no meaningful sound was heard anywhere else. So, for example, by walking down a ...
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Why is light produced when an underwater bubble is collapsed with a sound wave?

Why is light produced when an underwater bubble is collapsed with a sound wave? I have come across this fact on a page (similar to this) but can't understand "Why". I'm just curious about this ...
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Can random constructive interference with sound waves cause damage?

Any two sound waves have a random chance to constructively interfere with each other at a given spot and this will cause an increase or decrease in pressure. So is it possible that a large number of ...
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Why does sound move faster in solids?

I know that the molecules are closer together in solids, and I know thicker springs also respond carry waves faster than thinner springs, but for some reasons I can't understand why. The molecules ...
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Can we apply de Broglie's relations to sound waves?

Can we apply the de Broglie relations to a sound waves ? Is it possible? if yes how do you do that? what would be the mass(m) in the equation?
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Manufacturing Fresnel Lenses with Sound

I understand fresnel lenses are manufactured using CNC machines. I was wondering, if it would be possible to use sound to vibrate liquid silicon and then fast cool it into the standard form of a ...
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What are the limitations of performing music in space?

Canadian astronaut Chris Hadfield's song Space Oddity is making news around the world today. It makes me wonder: What are the limitations of performing music in space? Clearly, there is no point to ...
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106 views

Crackling of Speakers-Audio

Why do speakers make crackling noises when the pitches get too high for them? And why is it that lower end speakers tend to crackle more? If you try to feed in too high of a frequency, I would imagine ...
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720 views

Why do sound waves travel at the same speed moleculewise? (Same medium)

I don't understand what happens in reality (outside of wave theories). If I clap my hands I invest energy in the nearby air molecules, which move and transfer their energy to nearby molecules which ...
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449 views

Slinky reverb: the origin of the iconic Star Wars blaster sound

This is a fun problem that I came across recently, which I'm posting here for your delectation. We all love a good slinky: they can be used for all sorts of fun demos in physics. One example is the ...
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Lethality of sounds and extreme “loudness”

In theory, could pure sound be lethal? How loud would it have to be? Also, which events are the loudest in the universe, and how loud are they? I'm confining attention to events which occur regularly, ...