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Re : Re: psychoacoustically driven temporal approximation



Bonjour

I have never been a DSP wizard but cepstrum, wavelet and spectral centroid seemed a good idea. In any case using Kohonen maps to test via AI the quality of models, it appeared to me that a pseudo inversion of spectral data from a Fourier Transform was necessary to obtain a result compatible with mammal hearing.
In anycase Amplitude somehow should be the nomber one dimension. The ability of the brain to distinguish and name isolated frequencies is highy cultural and need specific training but energy related pack of frequencies is vital for recognition. I don't believe time is so important but resonance is.
Anyway this is a point of view of a composer who happen also to be a mathematician with some ircam notions of acoustics.

Best

Frédéric Maintenant
http://penserlamusique.canalblog.com

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From: JesterN Alberto Novello <jestern77@xxxxxxxx>;
To: <AUDITORY@xxxxxxxxxxxxxxx>;
Subject: Re: psychoacoustically driven temporal approximation
Sent: Thu, Mar 6, 2014 12:27:29 PM

Hi All thanks for the help. I'm checking the sources but your suggestions already popped up an idea that i'm trying. Useful brainstorming ;)
Thanks a lot
Alberto
 
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Il Giovedì 6 Marzo 2014 6:47, Richard F. Lyon <dicklyon@xxxxxxx> ha scritto:
Alberto, the question is not clear.  When you say "in the time domain" do you mean you are looking for alternatives to the widely used perceptual audio coders that use filterbanks? 

If "a spectral-weighted temporal approximation method" is what you want, don't try to "connect frequency components to specific samples in the time domain".  Frequency components are not a relevant concept in the time domain. 

Possibly what you want is something like LPC whitening with residual coding.  See for example:
Singhal, Sharad. "High quality audio coding using multipulse LPC." ICASSP, 1990.

Dick



On Tue, Mar 4, 2014 at 3:05 AM, JesterN Alberto Novello <jestern77@xxxxxxxx> wrote:
Hi all,
i'm trying to find a way to approximate the sample values of an audio waveform in time domain.
I want a method that takes care of approximating perceptually-relevant audio bands better than others.
Basically a spectral-weighted temporal approximation method. 
In my head it's not clear how to connect frequency components to specific samples in the time domain. 
Any DSP wizard out there with a good idea/papers ?
Best regards
Alberto 

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ALBERTO NOVELLO / JesterN
site: jestern.com
shop: jestern.bandcamp.com
audio: soundcloud.com/jestern
video: vimeo.com/jestern
 
|| | | ||| |  ||  || | ||||| || | || | ||| | ||||| | | ||| | |||| |  || ||||


If for any reason you wish not to receive any more messages from this email, please send an email with REMOVE as subject. I'm sorry for the inconvenience.
Se per qualsiasi ragione non desideri ricevere piu' messaggi da questo indirizzo, mandami un messaggio con REMOVE nel soggetto. Mi scuso per il disturbo.