Re: normalisation for spectral levels (Pierre Divenyi )

Subject: Re: normalisation for spectral levels
From:    Pierre Divenyi  <pdivenyi(at)EBIRE.ORG>
Date:    Wed, 24 Sep 2003 10:37:55 -0700

Christel,

Rather than getting hung up on formant-peak amplitude differences, it would
be more appropriate to look for changes in formant bandwidth and
peak-to-adjacent-trough ratio. Another way would be to see to what extent
the different exemplars diverge from either a generic neutral vowel or from
formants generated by a uniform tube, as suggested by Rene' Carre' (ask him
for reference, carre(at)tsi.enst.fr).

Pierre Divenyi

At 01:46 PM 9/24/2003 +0100, Christel de Bruijn wrote:
>Dear list,
>
>I apologise if the following question appears to be trivial.  I would be
>very grateful for an answer though.
>
>I would like to compare formant amplitude levels (in dB, measured from a
>spectrum) of a sustained vowel before and after a reading task. However, I
>adjusted the recording level for each vowel, in order to optimise SNR.
>
>Therefore, it does not make sense to compare absolute dB levels.
>
>I was wondering if I could do a simple normalisation for each vowel by
>substracting its RMS value (after converting it to a dB value) from its
>formant level.
>
>Could I then compare the formant levels, or is this too simple?
>
>
>Regards,
>
>Christel de Bruijn
>
>-----
>
>Christel de Bruijn
>Department of Human Communication Sciences
>University of Sheffield, UK