David, check out
http://www.ringthis.com/dev/wave_format.htm
http://www.lightlink.com/tjweber/StripWav/Canon.html
http://mathmatrix.narod.ru/Wavefmt.html
http://www.borg.com/~jglatt/tech/wave.htm
http://aulos.calarts.edu/pipermail/music-dsp/1998-March/020069.html

it might help you

>Hi everyone,
>
>I've been asked to build a database, which stores, compares, and analyzes the acoustic data (such as frequencies, amplitudes, sample rates)contained within a collection of small audio wav files. My problem is that I don't know how to extract usable data from a wav file.
>
>My questions are the following:
>
>How do I extract numerical data (frequencies, amplitudes, time data, etc.) from a wav file, so that I can store the data in a VFP table and perform analyses? If extracting that kind of data is possible, then how would I understand what the extracted numbers represent (for example, which numbers respresent frequency, amplitude, time, etc.)
>
>I've searched all over the web for information, but have only come up with some complex mathematical algorithms (such as Fast Fourier Transforms), which are constructed in languages such as Python, Java, or C. Unfortunately, I don't have knowledge of those other languages or the mathematics I came across. Basically, I have no idea how to convert wav files into the type of data I can manipulate in VFP.
>
>Does anyone have any knowledge of how to accomplish this with VFP coding? Is this even possible with VFP? Do I need to add a third party component to transform the file, or do I need to perform this in another language?
>
>Any advice would be appreciated,
>
>Thanks,
>Dave