Forums

need help about LPC 10

Started by Eris Ristemena February 28, 2000
hi all,
sorry to disturb you again with some silly questions, but i really hit a big
rock here .

1) the vocal tract of speech production can be modeled by LPC synthesis
filter, right ? it is shown by the spectral magnitude form of LPC
coefficient filter that looks like a spectral envelope of the speech signal.
am i right ? now, the problem is how about the phase response ? i have tried
thousand times that although the LPC coeff really models the spectral
envelope of speech signal, but the phase is totally different, so the
waveform of reconstructed signal will be totally different from the
original. Do you guys think it is okey ? i mean i read in Deller discrete
time processing of speech signal that the human ears can not sense the phase
different between two speech signal (phase deaf). But how come the sound of
the reconstructed speech is very buzzy and low intelegibility ?

2) the glottal filter, is it really necessary to use ? how necessary ? and
what could possibly be wrong if i'm not use it rather i use just a simple
periodic pulse ?

thanks in advance

Eris Ristemena

============
DSP Laboratory
Telkom School of Technology
Bandung, Indonesia
62-22-7564108 ext. 2325
http://students.stttelkom.ac.id/~eris_ristemena/
============



I am looking for binary data (words or phrases), decoded in lpc-10 and
usable on TI's obsolete TMS5220 chips. do you know any source or do
you have some predecoded data? I have a few including a disk from TI
with the dumps of 8 preprogrammed VM61.... Voice-memories.

BTW: are there any tools on the market to record voice and save in
lpc-10? I am a hardware-developing engineer and work on TI's DSP
cards. If anyone has an application for such a voice-recoder using a
TMS320C... please let me know. I remember a demoboard for TMS32010
from TI including a codec (in the late 80's...), but cannot find this
item anymore at our business...

Thank you in advance,

Michael Becker
Mannheim
Germany