Re: soundscape analysis? Get real!


Subject: Re: soundscape analysis? Get real!
From: Linda A. Seltzer (lseltzer@phoenix.Princeton.EDU)
Date: Thu Dec 16 1999 - 16:53:53 EST


The Matlab wavelet toolbox can be used to do CWT or
FWT analysis, so the software is no problem, except that
when I studied that package I found a bug in which
some of the arguments to one command were being called
in the wrong order. I reported it to the Mathworks
and they verified it, so I hope it's not present
in current versions. (This happened in 1997). If I
have time I will see if I still have any notes on this.
Also, some of the wavelets generated in Matlab are
normalized and some of them are not. You have
to study the package a lot before using it.

The other problem is this: Intuitively we can correlate
frequency with our perception, but do we really have
a feeling for a scalogram? The graph of a CWT will
tell us which translations and scales have high
correlation with the signal, but beyond that what
do you know intuitively from it? What is the
wavelet analogy to a formant? This is why you
don't see very many wavelet analyses around.

An FWT filterbank may have interesting analysis/synthesis
properties, but is there a wavelet synthesis method as
an analogy to SMS with sine waves? Wavelets might be
interesting with granular synthesis, but I have never
had the time to try it. Barry Truax, if you are
reading this, have you tried wavelets as grains?
Did it make a difference as compared to other types
of signals as grains?

Linda Seltzer



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