The Science of Sound: How Does It Travel from Source to Our Ears?

[donkeycopter]

We're doing sound waves in class at the moment, and basically I'm just trying to get a greater conceptual understanding of it by asking the simple question: how does sound get from a musical string, or a pipe into our ears?

We've done compressions and rarefactions etc, but I don't really understand how the sound actually moves in those waves to get to our ears?

I would love a sort of summary of how the wave theory is actually applied in this obvious scenario.

Thanks!

 

[DaveC426913]

We've done compressions and rarefactions etc, but I don't really understand how the sound actually moves in those waves to get to our ears?

I may be misinterpreting where exactly you confusion lies, but I'll give it a shot.


The waves are the sound. The sound is not carried in the waves, sound is what our brains interpet compressive waves as.


If you used a tiny pair of tweezers to grab your eardrum and wiggle it in and out 60 times per second, your brain would interpret this as a 60Hz hum. Note that you could move your tweezers in complete silence; it is the back and forth motion itself (by tweezer or by air pressure) that we perceive as sound.

Q: If a tree falls in a forest, and no one is there to hear it, does it make a sound?
A: No. Vibrations of the air are simply that - vibrations. It takes an ear and a brain to make that into a sound.

 

[donkeycopter]

Thanks, that's actually very helpful, but it wasn't what i meant exactly :)

Essentially if I was asked this question in an exam, how would you answer:

A guitar string is plucked, and a man 2m away hears the sound. Explain the process from the sound being created, to it being heard by the man in terms of sound waves.Obviously a stupid question that I just made up, but that's basically what I don't understand - how it all fits together.

 

[DaveC426913]

What piece of the puzzle exactly are you missing?

Guitar string moves back and forth 440 times per second (Middle A).
Guitar string's vibrations are imparted to the air in the form of cyclical compression and rarefaction of air density. Think of a http://www.google.ca/images?um=1&hl...Q&q=Newton's+cradle&spell=1&biw=1345&bih=624" made of air molecules.

Can you finish the rest?

 

[donkeycopter]

Basically I just don't know how I would answer that sort of question -what would your response be if it had to be 3-4 sentences, for example.

 

[DaveC426913]

Basically I just don't know how I would answer that sort of question -what would your response be if it had to be 3-4 sentences, for example.

Nice try. We cannot do your homework for you.

Write your ideas, we can help you.

 

[donkeycopter]

as I initially said, this is not a homework question. I can do all of the questions in class/homework questions, I just like to have a bit more conceptual understanding, hence I'm asking for an explanation of the concept here. I just asked for 3-4 sentences in the hope that you would give a more detailed reply, which you seem reluctant to do. Paradoxically however, your reluctance to respond would seem to negate any point to you replying, but who am I to question what you do :)

I just can't understand the concept! :)

 

[DaveC426913]

as I initially said, this is not a homework question. I can do all of the questions in class/homework questions, I just like to have a bit more conceptual understanding, hence I'm asking for an explanation of the concept here.

I just asked for 3-4 sentences in the hope that you would give a more detailed reply, which you seem reluctant to do.

I am not reluctant; I am bound by PF rules.

And so are you.

Write what you know, or what you think. We can correct.

(It would have taken less of your time and less of your writing to do that in the first place rather than repeatedly asking for someone else to write it for you. )

 

[donkeycopter]

I'm sorry, I don't understand your reasoning? I'm not asking for an answer, I'm asking for an explanation of a concept.

I have written all that I know 'through compressions and rarefactions' and I was hoping that somebody could explain how this is put into practice for me. How can I write an explanation for you to check, if I don't know the explanation myself, hence I am asking? :)

 

[DaveC426913]

https://www.physicsforums.com/showpost.php?p=66018", which you agreed to when you signed up.

You MUST show that you have attempted to answer your question in order to receive help.

Any and all assistance given to homework assignments or textbook style exercises should be given only after the questioner has shown some effort in solving the problem. If no attempt is made then the questioner should be asked to provide one before any assistance is given. Under no circumstances should complete solutions be provided to a questioner, whether or not an attempt has been made.

Now stop stalling. Just write what you know or think.

 

[Math Is Hard]

I'm sorry, I don't understand your reasoning? I'm not asking for an answer, I'm asking for an explanation of a concept.

I have written all that I know 'through compressions and rarefactions' and I was hoping that somebody could explain how this is put into practice for me. How can I write an explanation for you to check, if I don't know the explanation myself, hence I am asking? :)

Maybe we can back up.

1) Sound waves travel through the air and enter the ear
2) The pressure from these waves cause the eardrum (tympanic membrane) to vibrate

So , my guess is that you might want to know:

a) What happens before 1
b) What happens after 2
c) More clarification about the processes in either 1 or 2
?

 

[lewando]

Why not wiki "sound" for a detailed explanation? Then ask away on this forum if you need clarification. BTW, any relation to Joseph Heller?