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LPC Pitch Detection Help Required

Started by mgencarellli October 17, 2002
I am currently developing code using c6x DSK for determination of
pitch parameters for a simple LPC using the Sondhi center clipping
approach.

According to this method, the speech data is first filtered at 900 Hz
before it is clipped. What I want to know is :

1. Is this filter FIR or IIR, does it matter ?
2. What is the order of the filter required ?
3. What type of windowing is used ?

Also, I am confused on exactly what data is used to determine the
pitch. Is the signal applied to the 900 Hz filter a) raw speech data
read from the codec, demphasised, segmented into overlapping frames
and then windowed by a hamming window (that is what was used to
determine the gain, and refection coeeficient parameters), or b) just
the raw speech data read from the codec, segmented into overlapping
frames or c) just the raw speech data read from the codec, segmented
into overlapping frames followed by a hamming window, or something
else ?
Any help will very appreciated. Maurizio Gencarelli
Electronics Engineer
Royal Australian Air Force