Measuring the Speed of Sound in Air


Procedure:

I used a piece of narrow PVC pipe .389 cm in length.  I positioned the pipe on a table with
one end of the pipe protruding from the edge of the table.  I placed the microphone at the
opposite end of the pipe.  Then I created an impulse in the pipe by clapping my hands at
the end of the tube opposite from the microphone, recording these impulses with SND.  Then, 
I used the data in SND to measure the speed of sound.

Data:
 length of pipe = .389 m 
 t = time between impulse and the recorded reflection of that impulse

 d = vt

 d = .389 * 2 m 
  (The distance travelled by the sound before it hits the microphone again is twice the 
   length of the pipe.)

 t = .00225 s

 v = d/t = 345.8 m/s

Synthesizing the Pipe Sound

Using the echo function for the infinite impulse response (IIR), I approximated the sound of the pipe.

I used the following parameters for echo and issued the following command:


   (map-chan (echo .0024 .85) )

• Pipe Recording
• Simulated Sound