I have had reasonable success with the pitch tracking using LPC
analysis.  I don't know what is used for the pitch tracking, and whether
it is any different from pitch.  While working with LPC I noticed that a
lot depends on the quality/clarity of the input signal, sloppy speech
will result in garbage, basically.

As you may discern from the failure of early guitar synthesizers, pitch
tracking is a complicated problem.  For example, the fundamental
frequency of a 100 Hz tone may be absent, but because of the harmonics
(e.g., 200, 300, 400 Hz, etc.), you will still hear a 100 Hz tone,
because the periodicity hasn't changed.  The waveform may change because
of spectrum changes, but the pitch may still be the same.  So if you
want to compare one period with the next (I think you would use
something called autocorrelation for that) you have to take small or
even fairly sudden changes in the waveform into account.  Not to
disillusion you, but don't feel too bad if you haven't solved this
problem in one afternoon.

Job van Zuijlen

Josep M Comajuncosas wrote:
> 
> I´m sorry to insist on the topic, but... does anyone has a working
> example of a pitchtracker using the PITCH opcode, or anything else? I´m
> really needing it!
> Tnx
> 
> --
> Josep M Comajuncosas
> C/ Circumval.lacio 75  08790 Gelida - Penedes
> Catalunya - SPAIN tel. 93 7792243
> e-mail:          gelida@intercom.es
> ET Informatica de Sistemes
> e-mail: jcomajuncosas@campus.uoc.es