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Questions tagged [acoustics]

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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How is a computer able to replicate the sound of a human voice EXACTLY? What's in the computer that makes this possible? [on hold]

I am a music producer. If I take a sound or sample and use a professional tool such as REVERB inside the DIGITAL AUDIO WORKSTATION to make a completely whole new sound that nobody's ever heard before, ...
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Sound wave propagation through a wall

My question are actually two, but are somehow related. 1) Does a sound wave always (no matter what frequency) needs of the interaction (set in motion particles) with the element the wave is ...
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Why is sound attenuation greater in dry air than humid air?

I have just learned the surprising fact that the attenuation coefficient of sound in air depends strongly on relative humidity: at any given frequency, it can be several times larger in very dry air (...
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What force(s) comparable to material and acoustic damping dampens the ringing of merged black holes?

The "ringdown" that was detected after the merger of two black holes by LIGO in 2015 has been compared to the damping of a rung bell. Why doesn't the merged black hole ring perpetually? What force ...
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Is undamped reflection in a pipeline possible, under described circumstances?

Take $\,H_2O\,$ as the compressible medium (water hammer), and if we were to decide to compress it to the limit of breaking down to sub-components, holding in view the non-locallity of protons and ...
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1answer
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What relations between sound frequencies of a sound wave in motion that gets reflected from the wall occur?

Let's say you're driving forward by car and when you press the horn, the sound is reflected from the building in front of us. If we mark the frequency of the sound sent by $f_1$, frequency of the ...
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2answers
47 views

As a sound burst attenuates does it get longer?

I am trying to understand what a sound burst will look like after frequency dependent attenuation. I come from engineering / signal processing not physics background. If I am told as an engineer to ...
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1answer
30 views

The effect of wavelength on diffraction

I have learnt that the closer the slit width is to a wavelength source, the more it diffracts as it passes through it. Why is this the case? Also, how does this relate to low frequency sounds being ...
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2answers
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How can we pour water in a container without making noise?

We usually hear sound of splash when we pour water in a container.How can we pour water in a container without making noise? I think that the answer may be to pour it infinitesimally slowly.Am I ...
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4answers
130 views

Why can you hear sound over a wall?

I know it has to do with diffraction of sound, as it is a wave, but how exactly does this diffraction occur?
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2answers
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What happens to the frequencies of added sound waves?

What happens to the frequency when two sound waves add up to a complex wave? Example: I play a G3 on the guitar at 196 hertz and at the same time on the piano A4 440 hertz. What would be the "total ...
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Sensing different forms of energy [closed]

Can someone indicate whether electromagnetic radiation can be felt by the human body? And if so at what frequency? And what are the effects of exposure to it. Looking forward to your reply.
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Can the sound change the state of the medium?

The waves perform compression and rarefraccion in the medium where they spread, right?   when the rarefraction happens we should feel the medium in a liquid or gaseous state since the molecules ...
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1answer
22 views

Acousto-optic modulators

How can I determine which diffracted beam is +1 and which is -1 in the diffraction pattern formed by an acousto-optic modulator?
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1answer
60 views

Is there a way to inspect thin metal weld (2 mm - 3mm) by ultrasonic testing?

I am working with an ultrasonic device to inspect welds. So far, I have learned that the minimum thickness of the metal sheet for this inspection is 6mm - 8mm. But the product of mine has 3mm thick ...
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Equation of motion of suspended thin film

What is the equation of motion for a suspended thin piece of material (~film/plate/membrane)? Let's say the thickness of the film is in the order of 10 nm and it has infinite in-plane dimensions. I ...
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Acoustic streaming or acoustic radiation force domination

If you have some particles suspended in a fluid, and the system is exposed to pressure waves (from a piezo lets say), how can you find out whether the acoustic streaming or the acoustic radiation ...
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1answer
75 views

Calculating the resonant frequency of a metal pin

Is there a way to calculate the required diameter of a cylindrical metal (let's say aluminum) pin of a fixed length so that it has a specific resonant frequency? Let's say I have an aluminum pin that ...
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1answer
41 views

Why does the frequency of a wave change in the Doppler effect if it is a property of the source?

If the frequency of a wave is the property of the source emitting the wave, the number of times it vibrates per second, why does the frequency of an approaching or a receding ambulance or train change ...
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Does the frequency of a sound wave, similar to that of a light wave, reduce as it recedes from the earth's surface?

As a relativistic prediction, it is widely accepted that the frequency of a light wave receding from the surface of a massive plant is reduced due to its motion upwards against the gravitational field....
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City songbirds sing in higher pitch?

In this What I've Learnt Youtube video How Did Language Begin starting at the marked point, the author claims that the songbird in the city uses higher pitch to reduce echo bouncing. He later also ...
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3answers
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Why is it that sound at standard conditions always travels the same speed?

Say you have a small fire cracker. When it explodes, it imparts some kinetic energy to the surrounding air molecules, and they propagate that kinetic energy outward through collisions. Intuitively, ...
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1answer
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How does digital audio store the sound information? [closed]

I play with python wave module, and read some articles about digital audio, but still do not understand how the data are sufficient. The digital data is an array of amplitude vs. time. For 1s mono ...
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1answer
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Speed of sound in thermodynamically unstable phases

The general thermodynamic definition for the speed of sound is $$c_S=\sqrt{\left(\frac{\partial P}{\partial \rho}\right)_{S}}$$ But what if the material is in a non-stable state, e.g. during tension ...
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1answer
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'Drummy' sound when striking with a hammer

In building there is a common test for masonsry structures that involves striking the structure with a hammer and listening to the resulting sound. If the sound is ringing the structure is fine but if ...
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Relative speed of sound (relativistic velocities)

This question is about waves speed, not about waves frequency shift (I already know about Doppler's effect). I know that for all the mechanical waves, e.g. sound, the perceived wave speed depends on ...
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2answers
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Is it possible to use sound waves to move asteroids?

Does it seem feasible to use sound waves to deflect an inbound asteroid? Would it matter what frequency the sound waves are? Would it matter what the size or mass of the asteroid is?
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Make sound pipe for JSN-SR04T

JSN SR04T is an ultrasonic sensor. It has a large measuring angle 75degrees. I have read that a sound pipe can help the ultrasonic beam to be more focused. I found this https://autosen.com/en/Mounting-...
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2answers
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Closed end tube with anti-node

The experiment was about creating a sound wave inside a close ended resonance tube and finding the locations of maximum and minimum amplitude. (after adjusting the tube length that makes a standing ...
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4answers
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If water is incompressible, how can sound propagate underwater?

Since sound travels as longitudinal waves, sound waves should only be able to propagate in a medium through compressions and rarefactions. However, water, as a liquid, is generally treated as an ...
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1answer
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Why does a wave reflect on the edge of an open tube? [duplicate]

Why does a wave reflect on the edge of an open tube? There is nothing solid to make the wave bounce. Then why is it reflected?
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Why is the wave of a sound in a tube reversed? [duplicate]

Why does the blue wave when it reaches the edge of the open tube not follow its path instead it reverses red?
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Comparison of room acoustics simulation techniques

What is the state of the art technique for the numerical simulation of the propagation of a sound wave inside a room (room acoustics) regarding the time domain? I am specifically interested in the ...
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1answer
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How to calculate tube flow in layered ultrasound phantom using Doppler

Using a tank with the top filled with water and the bottom filled with a gel which is slightly denser than the water. Inside the gel is a tube tilted 60 degrees above the horizontal axis. The tube ...
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1answer
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How to explain the difference of attenuation of different pitch of sound by kinetic molecular energy?

How to explain the difference of attenuation of different pitch of sound by kinetic molecular energy ? I know that «sound of low frequencies travel farther in air than sound of high frequencies». ...
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Why does the speed of sound decrease at high altitudes although the air density decreases?

I understand that the speed of sound is inversely proportional to the density of the medium as shown here and as answered for this question. The problem now is that the speed of sound in air actually ...
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Is it possible to block sound? [duplicate]

Is it possible to block/eliminate particular noise sounds with artificially generated sound waves or any other ways?
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2answers
61 views

The shape of a crest and a trough on wave

what is the significance of the shape of a crest. For example, in the figure below, we can see that one graph of sound pressure shows sharp crests while the other shows smooth crests. How does this ...
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Why do male and female voice pronunciation is same in spite of different voice frequency?

I mean male and female voices are made up of different frequency range but when we produce same word suppose 'cake', we understand it as same.
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4answers
120 views

Sound frequencies travel at the same speed?

as the diagram shows sound frequencies travel at the same speed or each frequency has a given speed ?
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1answer
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What happens to a wave when the tube changes in diameter

everywhere they only show the single diameter tube, but they don't explain what happens to the wave when the tube changes its diameter Is someone kind enough to graph me how the wave changes when ...
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1answer
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the mechanism of sound generation of plunging jet

can anybody give me an explanation about what is the acoustic source for a plunging jet, like tap flow enter into a basin? is there any exiting theory like Lighthill theory in aero-acoustic to explain ...
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Pitch of balloon popping

How does the pitch of the sound of a balloon's pop change based on the pressure inside the balloon? Or does only the loudness of the sound differ? I assume the sound doesn't really have a definite ...
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2answers
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Pressure variation in a sound wave

My teacher told me that pressure variation is maximum at mean position in a sound wave. Though by proof of pressure wave and displacement wave, I am convinced but in understanding the physical ...
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1answer
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Why is the kettle loud, but the induction hob is quiet

The question: "Why is a kettle loud?" has been asked and answered many times, including on here: Why is boiling water loud, then quiet? What is the reason for this pattern of noise in electric ...
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What is the criteria that determines the difference between a plate and membrane, with material considerations?

So according to Venstel and Frauthammer in their 2001 book, the criteria for differentiating between rigid plates, thin plates and membranes is $a/h$ where a is a typical in-plane dimension (the ...
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2answers
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How are standing wave patterns created in tubes?

I get how standing wave patterns are created in strings: At a certain resonance/natural frequency of the string, a standing wave is created, increasing the amplitude of the sound, and standing waves ...
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1answer
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What is the difference between a Surface Acoustic Wave (SAW) (Rayleigh Wave) and a Leaky SAW?

I have come across leaky SAWs and I'm not sure what the difference is, and why some substrate cuts are listed as leaky SAW design. Trying to search for diagrams so I could see what the differences ...
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1answer
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Is there any relationship between a solid material's natural frequency and the speed of sound through the material?

It seems like there should be a mathematical relationship between the two - is there?
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Volume of a speaker needed to boil an egg [closed]

I have a fun question to ask that me and my friends couldn't figure out. If I was to boil an egg using a speaker, how loud would that speaker need to be? (Yep, this is clearly what keeps us physicists ...