Hi Listers,

My project uses a PIC12C509 to monitor sensors and then outputs various
simultaneous tones.  The tones are recorded on audio tape using a compact
cassette recorder.
When the recording is finished, I want to take the recorder to a PC equipped
with a sound card and create a .WAV file from it. (or similar?)
I then need to analyse the WAV file to extract the tones and  the times at
which they occur. I need to know with some precision the time interval
between changes of any two tones.  I  imagine that I need to run various
software filters on the WAV file to do it.  Can anyone tell me the
principles of software filtering or point me to web sites that may help? I
also need to know  about the file format of a WAV file. Can anyone help
please?

Best Regards,
Gerry Cox