Ryan wrote:


An FFT doesn't begin to disclose what you are looking for in
and of itself. It's no more than a view of the same data
with a different independant axis. It contains no
information at all about when things happen.


Is there any kind of analysis that does? I used FFT because that's
the only one I've really ever heard of. What if I perform a different
FFT for every second of the soundfile?

Very good! You've just described the STFT, short time
Fourier transform. It does give information about when
things happen with no greater resolution than the length of
the FFT. They can be overlapped for better resolution.
There is also the variety of wavelet transforms which allow
you to trade off the resolution in frequency and in time
according to a principle similar to Heisenberg's. They are
tricky to use.

The question remains to be answered in some detail what
information you want to obtain.



In any event, the ear brain does not do a Fourier analysis.
There are frequency dependant mechanisms but they are
totally ad hoc in terms of what nature found most useful for
subsequent analysis.


Was this a typo? I hope this doesn't offend, but every site I've
looked at about this says that indeed our ears do function as FFT
devices. If this is incorrect I'd very much like to know the turth
about the matter.

Nope. No offense taken. There is a _big_ difference
between a FT and an ad hoc and idiosyncratic feature
extraction mechanism that uses a very complicated organic
filter as part of its discrimination. The FT has a precise
mathematical formulation involving inner products with sin
and cosine signals at a precise set of frequencies. The ear
just doesn't do that. There is a gross similarity but
that's about all.

The Ghost could address this in some detail if anyone could
get him to do something besides insult people. When he was
young he published with one of the pioneers in the field of
hearing research, someone who I believe got a Nobel Prize
for it.

Is this what I'm asking for? I really don't know myself.

I'm having trouble figuring that out exactly too. :-)

In case you've received any new information that might help
you frame it better, would you care to try again?
Refinement to specs from vague ideas is not an uncommon
process in the user/marketing/engineering cyclic process.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein