I don't think that normalizing the sound before transforming will ensure that
the transforms (spectrograms) will all have the same maximum amplitude. The
best you can know is something like along the lines of "the sum of the squares
of all the amplitudes is the same as the sum of the squares of all the
transform's coefficients." So the max's don't have to be the same; to obtain
that you'd need to normalize after transforming.
SP
--- In "alizaleroux" <> wrote:
>
> I have a technical question which I suspect has a straightforward answer that
> I have somehow just not grasped...
>
> Does anyone know of a way to batch process a number of vocalizations (some
> very loud, some very soft) so that their maximum amplitudes are all the same,
> using AviSoft software?
>
> I have several 100 vocalizations that I want to analyze in AviSoft. As these
> recordings were done under natural conditions -- I had varying distances
> between the calling monkey and my microphone -- my spectrograms all have
> different amplitudes.
>
> I want to normalize all these spectrograms to have identical maximum
> amplitudes. There is a "normalize" function under the Edit/Volume menu but I
> can't seem to find the way to get all the different spectrograms to have the
> same amplitude maxima. If I specify a certain % in the Normalize tab the
> different calls still turn out to have very different maximum amplitudes.
>
> I can adjust the individual spectrograms' amplitudes to a specific value by
> multiplying/ dividing it with a different value for each spectrogram but this
> forces me to determine that value for each call individually, and apply the
> math to each spectrogram individually. I'm certain there has to be an easier
> way.
>
> Thanks so much for your help!
>
> Aliza
>
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