How can I graph a Sound?

Question

I need to find an instrument or a program that will display a graph of a sound in terms of pitch and time. One axis of the graph would span about 1 Hz and the other axis would cover anywhere from one tenth to one second. Anyone know where I could find such equipment/softwere, or if something like that is even available?

Answer 1

An oscilliscope with some digital processing is the firt thing that comes to mind.
Capture the sound waveform amd observe the intervals between the peeks over time to determine the change in pitch. Automate this calculation in the scope and plot the result on the screen.

Otherwise, you need a F-to-V (frequency to voltage) converter. An electrical engineer would know how to build one, but maybe you could find one readymade. A frequency meter might have an analog voltage output connector that you could then monitor with a plotter. I would check the Agilent catalog for a frequency meter with analog output.

Or else you can capture the sound into the computer using a sound card, and digitize it. You can then re-examine the saved digital file using a BASIC program that you wrote, and calculate the variation in pitch, and then you create your own graph. Or you can use a ready made program like Cool Edit to compute the variation in pitch for you.

Answer 2

there are such things as oscilloscopes, spectrum analyzers,
is this what your looking for ?

http://www.doctronics.co.uk/scope.htm

http://www.warren-wilson.edu/~physics/PhysSci/SoundOscilloscope/SoundOscilloscope.html

http://www.google.com/search?q=spectrum+analyzers+graphs+time+vs+pitch&start=0&ie=utf-8&oe=utf-8&client=firefox-a&rls=org.mozilla:en-US:official

http://www.sas.org/E-Bulletin/2004-01-09/features2/index.html