I thought you may be interested in this topic since I see some posts on Fourier analysis.
I used this method to get a signal out of an industrial grinding machine about a year ago. We were looking for signals related to characterizing the size of the crushed material based on acoustic signatures. It worked well enough. lol
Compared to a Fourier transform on a time based signal, this method adds the idea of 'when' the signature occurred not just at what frequency.
For example, play a music track and realize that 12.3 kHz was excited, also realize that this happened at 2 minutes and 31 seconds in the track.
Yup, another engineer geek. :)
Edited by ipm - 5/11/10 at 2:10am