What is Sound: Definition and 1000 Discussions

In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid.
In human physiology and psychology, sound is the reception of such waves and their perception by the brain. Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of 17 meters (56 ft) to 1.7 centimetres (0.67 in). Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges.

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  1. darkmamon

    What happens when sound wave loses energy?

    I'm a high school student doing the project about sound absorbing material When the sound is absorbed or loses its energy which of its value will change? pressure? wavelength? or frequency? (at first I though that the sound wave will just lose its amplitude but after the result,It look like its...
  2. S

    Listening to GW150914: Exploring the Sound of Gravitational Waves

    From what I can read of GW150914, it could be detected for a grand total of 200 ms, with frequency increasing from 35 Hz to 250 Hz. If it had been nearer, or the detector more sensitive, is it possible to predict what the duration of the emission would have been at frequencies over 16 Hz...
  3. O

    Do sound waves increase temperature?

    Do sound waves increase the temperature of the medium they are traveling through?
  4. P

    What is the speed of sound and time period of oscillating particles?

    I have a question to solve - A boy heard a sound of frequency 100 Hz at a distance of 500 m from the source of sound. What is the speed of sound? What is the time period of oscillating particles of the medium? I have approached the below way : We know that speed = distance / time...
  5. A

    What is the speed of sound in a rigid body?

    Homework Statement What will be the speed of sound in a perfectly rigid body? Given : In a hypothetical situation we have a rigid body find the speed of sound when it passes through the material. Elasticity of medium = ∞ Homework Equations velocity = √E/ρ ρ = density E = elasticity of medium...
  6. Cookiey

    Asymmetry in the Doppler Effect for sound

    I'm a bit confused about this. So say there's an observer and a source of sound. If the observer moves towards the source of sound, the frequency seems to increase because he encounters more wavelengths in the same amount of time. In a second case, if the source moved towards the observer, the...
  7. V

    What is phase difference and how to visualize it?

    what is phase difference and how to visualize it? i can understand it pretty well for sinusoidal waves,but how to visualize it for other type of waves like spherical waves,plane waves etc?
  8. Sophia

    Lingusitics What do foreign languages sound like to you?

    On 9gag I saw an interesting discussion about how people perceive foreign languages. You can write here how these languages sound to you, even when you don't understand them Hopefully no one will take this personally :) No offence intended So for me British English: aristocratic and melodic if...
  9. W

    Is sound a renewable energy or non-renewable energy?

    I've been searching the web for this answer and can't seem to find it anywhere. Can anyone help me? Is sound a renewable energy or non-renewable energy?
  10. T

    Amplification of sound in a pipe

    How loud would a 105 db speaker be in a 3 inch metal pipe?
  11. Sace Ver

    What is the speed of sound in air at atmospherical conditions?

    Homework Statement A student stands 86m from the foot of a cliff, claps her hands, and hears the echo 0.50s later. Calculate speed of sound in air. Known •86m •0.50s Homework Equations V=331.4+0.606T The Attempt at a Solution V=d/t V=86m/0.50s V=172m/s Is that the first step to the problem...
  12. Sace Ver

    Traveling Tine Waves and Sound

    Homework Statement The tine of a tuning fork, when struck, has an amplitude of 0.25cm. If the frequency is 150 Hz, what total distance with the tine travel in 1.00 min? Homework EquationsThe Attempt at a Solution Not sure how to solve this problem.
  13. Khoa

    Sound Insulation Testing Standards - Advice Needed

    Dear All, I'm seeking for EN/ISO/ASTM standards and where we can perform sound insulation testing for plastic foam/cellular products. Can you give me an advice? Thank in advance, Khoa
  14. L

    About the propagation of sound

    I'm trying to understand how a vibrating body produces oscillations in sound pressure. I've been through derivations and solutions of the wave equation for a string, but I don't understand the transition from waves on a string to sound pressure waves. How are the waves on a string or drum...
  15. G

    Fastest Terrestrial Sound Conduction Speed

    I stumbled across an interesting subject online http://boards.straightdope.com/sdmb/showthread.php?t=449378 Leads me to wonder what the fastest terrestrial sound conduction speed is.
  16. K

    Understand Sound Wave Propagation in Space

    Why does sound waves propagate trough space with areas of lower and higher pressure, why does not pressure just equalize without waves? Thanx for answers.
  17. B

    Sound waves in carbon dioxide -- I think book answer is *wrong*

    Homework Statement Sound waves can be refracted when they travel through balloons filled with different gases. How would the motion of a sound wave be changed if it traveled through a balloon filled with carbon dioxide?BOOK ANSWER "Being more dense than air, the carbon dioxide in the balloon...
  18. H

    How do standing waves produce sound?

    Hi i've been taught that standing waves do not transfer a net energy. but standing waves are formed in instruments, and we can hear them - so some sound energy/kinetic must be transferred to surrounding particles to reach our ears? how does this work? please could you help me if my understanding...
  19. ft92

    Question about sound absorption/reflection

    Hello everyone! I would like to share with you the results of an experiment we did in the first year physics lab and ask for your point of view to understand why we got the results that I'm about to tell you. The experiment was nothing too fancy, we were trying to test how well materials...
  20. M

    Is this wave interference? Sound mixing problem.

    This is my first post here, so hello to all. I came here looking for advice. I am far for considering myself even a newbie regarding physics, I have huge gaps in knowledge. However, as I happen to "know my way around computers", I am helping my friend in her art project. Sparing you the...
  21. A

    So.... The multiverse is unscientificly sound?

    According to science everything has a beginning and an end, even infenent genius. But the multiverse has no beginning and no end, it just keeps going. So in that line of thought, is science really fact, or just people trying to explained things like ancient cultures and their deities? btw, I'm...
  22. H

    Depth of a well (using speed of sound)

    Homework Statement A stone is dropped from rest into a well. Th sound of the splash is heard exactly 2.00 s later. Find the depth of the well if the air temperature is 10.0 degrees Celsius. Homework Equations How does the speed of sound play a role in this? How can I find the depth? The...
  23. V

    Why Does Sound Get Produced? Exploring Vibrations & More

    Why is sound produced? Say, for example, when a stone hits a tin box a sound is produced. Why is this sound produced? Even if the sound is produced in the ear, we generally say that the vibrations of the ear drum produces the sound, why is it produced. Why does vibrations produce sound. Even a...
  24. D

    How does a whip break speed of sound?

    I'm trying to understand by what mechanism a whip can multiply the velocity of the initial arm motion until it reaches the speed of sound, how is it doing this?
  25. Observeraren

    Vibrations in a glass with water.

    So I just poured water in a glass to clench my thirst. Hit the 2/3 empty glass with a pen and a high frequency started resonating for a brief moment, which I percepted as sound. When I tilted the glass the tilt resulted in change of frequency. When the glass was empty there was no change in...
  26. U

    What is needed to allow sound to move an object

    I am interested to know what governs whether an object in the path of a sound wave will feel force. For instance will low frequency sound have more of an effect than high frequency? What difference does the material or shape of the object have on whether it would feel any force from the...
  27. P

    How to make the sound of my doorbell circuit louder?

    I have used one UM66 IC, one BC547 Transistor and one 100 Ohm resistor. The circuits of door bell are as follows but same result. The loudness is extremely poor against both the circuits. How can I increase the loudness? Would you please help me in this regard?
  28. 3301

    In one sentence: What is sound?

    Fine formula and explanation is perfect.
  29. S

    Is sound amplified underwater?

    Hi all, Is sound amplified underwater? My reasoning is if a sound is louder underwater than it is on land, then it has been amplified. Is this correct?
  30. Ronie Bayron

    What Is the Speed of Sound and Vibration in Solids?

    Say, I have 10 Km (1m dia.) exposed pipeline under construction phase. 9 Km of the pipe line was already done. Its so happen that at the next pipe length installation, the plane operator mishandled the pipe and it collided at the end where connection should be made, big time that the magnitude...
  31. T

    Sound transfer through duct wall?

    The attached image shows the top of a residential air handling unit, and how a flexible silencer (right) and a spiral duct (left) is attached. The duct is steel, and the silencer aluminium. The owner proposes that fan noise will transfer to the room through the centimeter wide piece of exposed...
  32. J

    Why Does Light Interference Differ from Sound Interference?

    Homework Statement Homework Equations I α A2 The Attempt at a Solution My teacher told us that if the source is a light source, then the answer would be B, why? Why would the intensity be the same for each maxima? And zero intensity when at minima? I thought its amplitude will decrease as it...
  33. H

    Can Multisim Import and Process Sound Files Through a Circuit?

    Is it possible to import a sound file into multisim and run it thru a circuit eg a passive low pass RC filter and send the signal to a speaker and save the clean signal say as a wav file.
  34. D

    Calculating Power at source from Intensity at distance R

    Homework Statement An enclosed chamber with sound absorbing walls has a 2.0 m × 1.0 m opening for an outside window. A loudspeaker is located outdoors, 46 m away and facing the window. The intensity level of the sound entering the window space from the loudspeaker is 42 dB. Assume the acoustic...
  35. K

    Intensity and Sound Level question.

    Hello, I only have 1 question left to finish my physics homework, and it has to do with sound and intensity. I am having some trouble figuring out how to solve it. Here is the question: At a distance of 17 km, a 177 Hz horn, assumed to be an isotropic point source, is barely audible. At what...
  36. S

    Understanding a sound spectrum analyzer output

    Hi, I am just trying to understand the output of a sound spectrum analyzer. There are three dimensions 1) Time 2) Frequency 3) Volume (db) I am confused about few things here: 1) How should I perceive the volume dimension here? 2) Why are the db values negative here and w.r.t what reference...
  37. rpthomps

    How long would it take a sound wave to travel 150m

    Homework Statement The sound speed in air at 0 degrees Celsius is 331 m/s, and for temperatures within a few tens of degrees of 0 degrees celsius it increases at the rate 0.590 m/s for every degree celsius increase in temperature. How long would it take a sound wave to travel 150 m over a path...
  38. Lokesh7890

    Can Electrical Signals Be Converted to Sound and Used to Read Minds?

    Hi friends I'm new here I just want to know if we can convert electrical signals to sound
  39. kostoglotov

    Why is the open end of a tube a node for a standing wave?

    I understand, from my textbook, that certain frequencies of sound (depending on the length of the tube) will reflect off the interface between the air in the tube and the air outside, that this interface is a discontinuity. But in all other cases where discontinuities caused (partial)...
  40. J

    Calculating Speed of Sound in Nickel using Atomic Properties

    Homework Statement From WebAssign: One mole of nickel (6.02e23 atoms) has a mass of 59 g, and its density is 8.9 g/cm3. You have a bar of nickel 2.44 m long, with a square cross section, 1.8 mm on a side. You hang the rod vertically and attach a 45 kg mass to the bottom, and you observe that...
  41. F

    Sound Intensity: Reduce by 35 dB, Factor Calculation

    Homework Statement If you install special sound-reflecting windows that reduce the sound intensity level by 35.0 dB , by what factor have you reduced the sound intensity? Homework Equations Δβ=10Log(I/I°) The Attempt at a Solution I°=10^-12 I=I°-35 35=10^1.5440680...
  42. Gagan Raj

    What about converting sound energy to electrical energy?

    is that possible pls help me!
  43. P

    Sound Waves - Dropping a coin down a well

    The question is: You drop a coin down a well. After 3.2 seconds you hear the sound of the coin splashing into the water surface below. How far below lies the water surface in the well? After doing all the work the answer comes out to d = 46.0 m. However, when solving for "d" I had to solve a...
  44. W

    Sound Problems in Win (Lose) 8.1

    Hi All, I am having trouble with both sound input and output in windows 8.1. Error message is " The Audio Service is not running". I eventually find out the system believes there are neither audio input nor output devices installed. Still, when I go to device manager, the audio system is clearly...
  45. E

    Speed of bowling ball involving speed of sound

    Homework Statement A bowling ball traveling with a constant speed hits the pins at the end of a bowling lane 16.5 m long. The bowler hears the sound of the ball hitting pins 2.5 s after ball is released from his hands. What is the speed of ball, assuming speed of sound is 340 m/s? Homework...
  46. K

    Sound standing waves paradox....

    If you seal a loudspeaker at the end of a tube and close the other end of the tube you will get standing waves; but what are the boundary conditions at the speaker for the sound pressure wave? Pressure =0 or Pressure = MAX? I find no mention of this in the literature. To find out I performed a...
  47. nilesh_pat

    Causes for producing Sound while crossing sound barrier

    What causes to produce sound (like boom) when crossing a sound barrier. With regards Nilesh.
  48. Ajit Kumar

    Why is velocity of sound inversely proportional to square r

    A. Sound is nothing more than a local disturbance whose propagation is facilitated by the collisions between particles B. The distances between molecules in solids are very small, i.e., solids are more dense - as compared to liquids and gases. Because they are so close, than can collide very...
  49. Y

    Need help with physics experiment (Speed of sound)

    < Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > Last week we had to conduct an experiment with the aim of determining the speed of sound. I decided to play with doppler effect. I was more or less sure what I had to do but then the teacher came...
  50. K

    Frequency of sound involving bamboo flutes

    Dear all, I have been attempting to create a range of bamboo flutes with different lengths for my physics practical. I am trying to calculate the theoretical frequency that should be produced by a particular length of flute, but all my flutes have different diamaters and I am searching for an...
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