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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Cigarette butt sound wave

What happens when I extinguish a cigarette in a recipient with some water in it ? It goes like pshhh, but what creates the sound wave ? Is it the water evaporating ?
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Why do I hear a squeak in my pipes when my neighbour runs his water?

I just installed a new water-heater in my apartment. Now, I hear a squeak from some rooms every time some neighbour runs the water. Could not hear this before, and the pipes are all the same diameter ...
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79 views

Resource on history of acoustics

Shortly: I am looking for a good resource (article, book, chapter in a book, introduction in an article...) about history of acoustics, I will be glad for any recommendations. By acoustics I mean the ...
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55 views

How is possible to hear mechanical sounds in space?

In the footage taken by U.S. astronaut Terry Virts during spacewalk (EVA) on the International Space Station on 25.02.2015, sounds can be heard while in space. I can understand "shaking" sounds while ...
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43 views

How to get the pressure amplitude at any spatial point?

Working on the pressure equation from the linearized euler equations, I stumble across a very simple problem : How, from the pressure solution of the specific equation (see ...
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6answers
506 views

Physics of how the cochlea isolates frequencies along its length?

Can anyone explain the separation of frequencies along the basilar membrane of the cochlea please? (equations would be nice) I understand it being related to the resistance caused by fluid in the ...
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28 views

Sound and Effect of frequency shift [closed]

I am a real non-physicist. I am playing with sound in MATLAB. I observed the outcomes and wonder why. After I applied frequency shift to a sound, Sound was not clear any more. What is the reason? ...
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29 views

Doppler effect exact expression

I'm looking for references about the doppler effect derivation, I'm interested by the exact expression and discussion about the approximation that are commonly made (I'm in the field of underwater ...
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111 views

How does a sonic black hole (or dumb hole) work?

I came across this term and I heard they used sonic black holes to detect something analogous to hawking radiation, but I have failed to find sources which explain how exactly they work and how they ...
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62 views

Why does a double-slit experiment with sound waves never result in complete destructive interference?

Today, I find a question that if the speakers are set in parallel towards the wall. It has no complete destructive interference due to difference in distance from the point to each speakers, which ...
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56 views

Can sound be used to deviate objects?

I'm doing a fictional history, where there is a very advanced army but i like to keep things real, and my knowledge of physics is very limited...but i know sound has been used to levitate objects ...
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2answers
47 views

How can I easily measure the distance between well head and water surface continuously

Reprhasing the question is a more open ended manner: Method 1: Use a pipe and measure it's resonance. Given a closed pipe from 10 to 300 feet in length, and roughly 5/8" in diameter, made of 1/16" ...
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111 views

Positions and corresponding terminology of “acoustics energy”?

From limited knowledge, decades ago, dating back to the nineteenth century: Ohm's law of specific acoustic energies was the first biological application of Fourier's theorem. Actually, it was ...
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92 views

Physical intuition for quadrupole source

In his Theory of Vortex Sound M. S. Howe defines sources "mathematically" (i.e. dipole is a source that could be described as a vector and than there is proved that it's equivalent to a two point ...
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80 views

Relationship Between Acoustics and Gravity?

I have studied some physics in college, but not enough to know the answer. My motivation: sound (or acoustics in general) does not exist in a vacuum, which means that acoustic waves are only present ...
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9k views

Does the human body have a resonant frequency? If so, how strong is it?

Inspired by this question on Music beta SE, I'm wondering if the human body has a strong resonant frequency. I guess the fact that it's largely a bag of jelly would add a lot of damping to the system, ...
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512 views

Would fog impair echolocation abilities?

I was driving down a major highway today and the fog was thick enough I could barely see 40 ft in front of me. I then wondered if I had had some other form of perception could I have perceived my ...
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128 views

Are there any natural phenomena on Earth that involve supersonic speeds?

Are there any natural phenomena on Earth that involves supersonic speeds, other than volcanic tephra and meteoroids? Edit: By natural I mean not man made like airplanes, rockets, missiles, bullet, ...
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121 views

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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188 views

Speed of Sound/Push in Supersonic Flight

I've learned from things like the Veritasium Slink Drop and the old "break the speed of light by pushing on the end of a very long pole" thought experiment that objects have a "speed of push" which is ...
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556 views

Why do you hear an acute sound when you rub your shoe on the floor?

Sorry for the silly question, but I've been wondering about this for quite some time. After raining when I get home I rub my shoe's wet outsole on the floor and I hear an extremely acute (high pitch) ...
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148 views

What is the exact physics behind sonic levitation

Me and a group of friends decided to choose sonic levitation as our research topic. However, after looking up the theoretical background, we hit a roadblock: (Here is an image of a standing sound ...
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67 views

Significance of higher harmonics

I am analyzing a noise signal and have identified the fundamental frequency of a tone and it's higher harmonics. Say for example given the signal below, The fundamental frequency has a sound ...
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4answers
216 views

If a bell is rung in a perfect vacuum and is suspended by opposing magnets will it ever stop ringing?

As far as I am aware a bell rung in a perfect vacuum would only lose energy and stop ringing due to friction between the bell and the hanging mechanism (due to the lack of air resistance). Therefore ...
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154 views

How quickly should a fluid come to hydrostatic equilibrium?

Let's say I'm holding a one-liter water bottle, full of water, which I then drop. Before dropping the water bottle, the equilibrium is for there to be a pressure gradient in the water canceling the ...
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6answers
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What is the speed of sound in space?

Given that space is not a perfect vacuum, what is the speed of sound therein? Google was not very helpful in this regard, as the only answer I found was 300 km/s, from Astronomy Cafe, which is not a ...
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Submarine Speed Detection [closed]

A submarine can use sonar (sound traveling through water) to determine its distance from other objects. The time between the emission of a sound pulse (a “ping”) and the detection of its echo can be ...
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392 views

If the source of sound is vibration, why can't we “hear” a object whose molecules are vibrating?

According to our physics textbook, the source of sound is vibration. According to our chemistry textbook, substances in solid state have molecules vibrating in a fixed position. So why can't I hear my ...
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How do megaphones work?

I have gone through a lot of Google links before bothering you people. I wanted to know how megaphones work. I only got answers like they direct sound in one direction only (most probably in direction ...
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3answers
179 views

Resultant frequency if 3 harmonic notes (a chord) is played

If I know the frequency of individual notes being played (let's assume D, F# and A), how do I determine the final frequency if they are played (nearly) simultaneously as a chord. To put the problem ...
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72 views

How can the speed of sound increase with an increase in temperature?

I was reading a textbook. I found that it was mentioned the speed of sound increases with increase in temperature. But sound is a mechanical wave, and it travels faster when molecules are closer. ...
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51 views

Is sound a Nambu-Goldstone mode?

The usual sound exists in solids, liquids, and gases, as a long-wavelength excitation with linear dispersion. Can its presence be attributed to the spontaneous breaking of some symmetry? In other ...
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7k views

How does gravity affect sound waves? [closed]

Someone asked me this question and I don't think I gave him an adequate answer (I was trying to think of the extreme case - that of neutron stars)
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21 views

Finding the time when we hear sound? (Reference Frames )

So a person stands at a far distance from an audio device. The audio device emits a sound and the person wants to get the exact time. He knows about speed of sound and has a meter stick to measure his ...
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113 views

different liquid in a container produce different sound

Does the type of liquid in a container affect the sound it produces? example like milk, water and coffee produce a minute different sound
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69 views

What is the physical origin of acoustic modes in a duct?

Lets deal with wave propagation in a cylindrical duct. We ask the question: "what is the general form of a pressure wave which can propagate through the duct?" In answering this, we assume that the ...
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40 views

Limits for the linear wave equation

In acoustics and continuum mechanics the following wave equation (for Speed of Sound $c$) for the pressure field $p$ is well-known: $\partial_t \partial_t p = c^2 \Delta p$. This wave equation can be ...
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82 views

Ice when melted at zero gravity [closed]

I wish to know the behavior of ice at zero gravity, how ice will behave when melted at g=0? Thanks
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Why doesn't light, which travels faster than sound, produce a sonic boom?

I know that when an object exceeds the speed of sound ($340$ m/s) a sonic boom is produced. Light which travels at $300,000,000$ m/s, much more than the speed of sound but doesn't produce a sonic ...
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159 views

Help me understand resonance

I don't fully understand how resonant chambers work. My confusion stems from the fact that the chambers are passive elements or filters, yet somehow are able to amplify the sound. Questions: How ...
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1answer
164 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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52 views

Any general method of determining changes in speed of sound with pressure?

I need to correct speed of sound measurements in various gases for changes in ambient pressure, typically 700-1100 mBar. Is there any general theoretical model available for this? Especially something ...
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28 views

Ratio of two RMS values in recorded audio

A quick(ish) question: I produce music and I am having a discussion on the difference between two RMS values in a specific record Nero: The Thrill (Porter Robinson Remix). In the verse, the RMS is ...
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36 views

How to calculate the radiation impedance of the horn loudspeaker?

The mouth of the horn is circular and there are many models in order to approximate the radiation impedance, such as: massless circular piston in an infinite baffle, unbaffled massless ...
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1answer
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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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3answers
446 views

What are the rules for breaking a glass with your voice?

So, this morning I woke up and remembered something I discussed about with one of my friends: Can human voice really break a wine glass? So I looked it up and after checking many websites and ...
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60 views

Singing for physicists: How to resonate by body cavities with my voice?

My body has various cavities, such as my throat, mouth, chest, and nose. This cavities have resonant frequencies. I also have a voice box, which creates sound. How do I create sounds at the resonant ...
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1answer
36 views

Reflection of Sound wave (Pressure Wave)

I want to study about the phenomenon of reflection of pressure waves as in an open ended organ pipe. Please suggest a suitable resource? I know about the harmonics in a stretched string and I can use ...
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22 views

Different noise when knock on a hollow wall

This might have a very simple answer, but I was wondering whether there was more to it. When we knock on a wall, the noise is different depending on whether there's a hollow space behind it or not. ...
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A simple question about frequencies, vibrations and engineering

I am a composer that likes science a lot but I am less than amateur at it. I am trying to start understanding how low frequencies (below 100hz let's say) behave. The intent is to find solutions to ...