Re: Audio to pitch is not a solved problem. Don't expect it to work for general cases anytime soon!

From: phil osborn (
Date: Sun May 28 2000 - 00:11:15 MDT

>From: Eirikur Hallgrimsson <>
>Subject: Audio to pitch is not a solved problem. Don't expect it to work
>for general cases anytime soon!
>Date: Fri, 26 May 2000 02:28:31 -0400
>I see a lot of people pointing optimistically to some of the roadkill
>on the way to the fantasy of being able to hum and hear trumpets.
>It's almost all roadkill. It'll happen eventually, but it will be
>the result of using on the order of four different "pitch-guessing"
>processes, and voting. And to get that to work will require
>recognizing the instrument used as input. This is, after all, what a
>human does. Our auditory processing is truely remarkable. The real
>reason that we haven't solved this problem is that the goal has a
>large fantasy element--it couldn't be made to work even using magic,
>unless you somehow hacked the user's perceptions.
>Assuming that you can build hardware that somehow does discriminate
>pitch as fast as we do, you have the latency issue that you are now
>ready to start playing the note that the human audience has already
>heard from the source (whistle, guitar-string or whatever) and you
>start late. You just can't make this work in real time performance
>situations, even if you can hide the original control signal from the
>audience. The control signal matched the timing of the other
>performers, but the resulting tone is unavoidably late. Playing solo
>doesn't solve it either because what you are hearing is the note that
>you were humming, played as trumpets, not the one that you are trying
>to hum right now. The actual note-rate (tempo) that can be
>accomplished is really slow.
>I'd love to see a real solution, but I don't think you can get there
>even with use of EEG.
In the '80's there was a product called "pitch-rider" for the Amiga that
alleged to do just what you say is impossible. I saw some impressive
demonstrations, with guys humming or whistling and having it come out as
MIDI guitar chords, or organ chords. One guy who actually claims to have
the product, however, did say that it wasn't really that accurate in real
time - those guys must have practiced a LOT. I would have liked to have had
it just for sequencing, however.
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