SV: [music-dsp] Pitch Perception - with an inharmonic overtone
ansum at online.de
Sun Nov 7 09:42:20 EST 2004
Thanks for answering.
> As for pitch perception, there are some studies of mistuning one
> single partial of a harmonic spectrum. As expected, this raises
> the pitch, but only if the mistuning is small enough - otherwise this
> partial is segregated and heard out as a separate tone.
Yes, this is very much in line with my own observations. I would assume
that the brain uses the harmonic pattern as a blue print for tonality as
long as a deviation is relatively small, it can be compensated driving
the percepted pitch in it's direction. only when it 'breaks the mold' so
to speak it gets rejectd, which is heard as a dissonant tone.
> What kind of spectra are you working with?
Everything that can be composed of up to 16 modes. I know this is a
relatively small number (drums can easily have hundereds of modes for
example). However my computer won't calculate more in realtime. And I
still like the results. :-)
> (...) Unfortunately, this algorithm is far too simple to deal with
> many types of inharmonic spectra, and so it often fails to detect
> the perceived pitch.
This is still an interesting approach. Since I have full control over
where I place the resonant frequencies of my model, I won't have to do
an analysis. I rather would want to implement the intonation correction
as a part of the frequency calculation.
i.e. while the user twiddles some knobs to spread or otherwise
manipulate the spectrum the frequencies should be calculated in a way
that the composite sound has a defined pitch (as long as when this is
the desired result)
Thanks for the link! This looks like a great ressource. I'll have to
spend some time reading there.
Risto Holopainen wrote:
> Hello Andreas and the rest of you. I haven't posted to this list before, though I've been here for some time. I'm primarily a composer, but also interrested in synthesis and DSP things.
> As for pitch perception, there are some studies of mistuning one single partial of a harmonic spectrum. As expected, this raises the pitch, but only if the mistuning is small enough - otherwise this partial is segregated and heard out as a separate tone.
> I don't know if anyone has come up with a formula for relating arbitrary inharmonic spectra to their perceived pitch yet, this tends to be a complicated matter. What kind of spectra are you working with?
> However, I also thought about this problem a while ago, and tried to write a program to guess the pitch of a spectrum. The general idea is to multiply the spectrum with periodic functions such as (0.5cos(2pi f) + 0.5)^4 and integrating. As f goes from 20hz to about 4khz (the useful range of pitch perception), the maxima would indicate candidates for the perceived pitch.
> Unfortunately, this algorithm is far too simple to deal with many types of inharmonic spectra, and so it often fails to detect the perceived pitch.
> Suggested reading: Albert S. Bregman's Auditory Scene Analysis. Doesn't provide an answer to your question, but may be useful.
> Albrecht Schneider's Tonhöhe - Skala - Klang may be something. I'm not fluent in german though, but it looks interresting.
> There's also a resource on the tuning of church bells:
> I hope this helps.
> Risto Holopainen
>>From: Andreas Sumerauer [ansum at online.de]
>>Subject: [music-dsp] Pitch Perception - with an inharmonic overtone spectrum
>>I am currently experimenting with modal synthesis and found that the
>>perceived pitch is very much dependent on the overtones. If the spectrum
>>is spread just a little bit the perceived pitch of the sound will not be
>>equal to the fundamental anymore.
>>I am just wondering wether it is possible to predict the perceiced pitch
>>when the (inharmonic) spectrum is known. are there any rules that allow
>>to precisely estimate the pitch?
>>This would help me to implement an automatic retuning when the spectrum
>>I would be greatful for any hints or literature on the topic.
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