Newsgroups: comp.speech
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From: lenzo@itl.atr.co.jp (Kevin A. Lenzo)
Subject: Re: Algorithm for DFT to log frequency scale, anyone?
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References: <3cgcrm$c6@cat.cis.Brown.EDU> <LUCKE.94Dec16104403@atrq28.itl.atr.co.jp>
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Date: Mon, 19 Dec 1994 05:19:07 GMT
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In article <LUCKE.94Dec16104403@atrq28.itl.atr.co.jp>, lucke@itl.atr.co.jp
(Helmut Lucke) wrote:
> In article <3cgcrm$c6@cat.cis.Brown.EDU> Thanassi Protopapas
<protopap@bekas.cog.brown.edu> writes:
> 
>    I need to compute the audio spectrum of some speech signals on
>    a logarithmic frequency scale (i.e., I want to evaluate the 
>    Fourier transform on frequencies equidistant on a log scale).

[snip]

> If you do want something Fourier-transfrom-like, I would say
> the following:

[snip]

Another option is to forget about the DFT and use a bank of filters
distributed in the way you need them.  For instance, you can check
the Gammatone filters in either the Auditory Image Model or
LUTEar.

AIM host:     ftp.mrc-apu.cam.ac.uk  in  pub/aim
LUTEar host:  suna.lut.ac.uk         in  /public/hulpo/lutear

(both are available by anonymous ftp)

Kevin
lenzo@itl.atr.co.jp
