On Tue, 11 Mar 2008 09:19:08 +0100 Bryan Jurish moocow@ling.uni-potsdam.de wrote:
moin Marius, moin list,
sorry, haven't tried it yet -- i'm more interested in getting funny noises out of pd than into it ;-) Maybe Andy Farnell has done something along these lines?
No, I've nothing much to offer here except that LPC (linear predictive coding) is one way I believe vowel recognition can be done.
Perry and Eduardo Miranda both mention it in their textbooks in this context and I'm pretty sure there's a whole stack of papers out there from speech recognition people that will point you in this direction.
LPC delivers the pitched or noisy component, plus a residual error, plus a profile of a filter that would reconstruct the orginal signal if the pitched/noisy part were subjected to it. I can't remember exactly how this works, but there is a way to turn the LPC analysis into the coefficients for this filter. In Csound it works as an analysis resynthesis pair.
I think only three strong poles need to be identified then pattern matching to the spacing of these formants should give you the vowel, independently of the voice age/gender/louness etc when you look at the ratios (say the first and second distance vs the first and third)
Speculating wildly (e.g. without any experience in vowel detection), I think [fiddle~] probably won't work on its own: it's designed to detect the fundamental frequency (f0), whereas vowels will differ primarily in the formants: maybe an fft approach would work? or perhaps you could have several instances of [fiddle~], tweaking the parameters such that each detects a single formant? ... just wild speculation ...
marmosets, Bryan
On 2008-03-11 00:35:42, marius schebella marius.schebella@gmail.com appears to have written:
hi, I wonder if anyone did vowel recognition with Pd. Maybe ed kelly? or brian j.? can it be based on fiddle~ or does it neeed more/other objects/technology? marius.
-- Bryan Jurish "There is *always* one more bug." jurish@ling.uni-potsdam.de -Lubarsky's Law of Cybernetic Entomology
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