Newsgroups: comp.speech
Path: lyra.csx.cam.ac.uk!doc.ic.ac.uk!aixssc.uk.ibm.com!ibm.de!Munich.Germany.EU.net!Germany.EU.net!EU.net!howland.reston.ans.net!noc.near.net!analog.com!analog.com!nwd2sun2.analog.com!az
From: az@saturn.analog.com (Alex Zatsman)
Subject: Re: Extracting formants with LPC.
In-Reply-To: aj453@um.erisoft.se's message of Fri, 22 Jul 1994 10:19:39 GMT
Message-ID: <AZ.94Jul22163500@saturn.analog.com>
Sender: usenet@analog.com
Organization: Analog Devices Inc, Norwood MA, USA
References: <1994Jul22.101939.22251@um.erisoft.se>
Date: Fri, 22 Jul 1994 21:35:00 GMT
Lines: 17

In article <1994Jul22.101939.22251@um.erisoft.se> aj453@um.erisoft.se (Anders Jansson) writes:
>    Does anyone have/know of some code or algorithm for extracting
>    formants from LPC-analysis.
>    Whatever code/algorithm exsisting will be fine fine. 

The   algorithm  is   relatively simple:   you   take the    resulting
coefficients,  say a[k],  and   find maximum  absolute values of   the
corresponding polynomial on the unit  circle. The arguments, or rather
their angles, correspond  to  formats frequencies.  The  polynomial is
expressed (in LaTeX notation) as

	1 + \sum_{k=1}^n a_k z^{-k}.

Hope it helps.
--
Alex Zatsman,     Analog Devices, Inc., (617) 461-3729
alex.zatsman@analog.com
