Reply by Raghavendra K S December 1, 20052005-12-01
Good approach is to use 120 sample frame with 80 sample overlap and SF=8khz Reffer ETSI Distributed Speech Recognition Frontend to understand preprocessing required. Its here http://webapp.etsi.org/workprogram/Frame_WorkItemList.asp?qETSI_STANDARD_TYPE=%27ES%27&qETSI_NUMBER 1108&qTB_ID=&butExpertSearch=++Search++ Besta luck ~rAGU

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From: "Gina Upperman"
Subject: Simple Speech Recognition Program with LPC

Hi All -
I am trying to make a simple speech recognition program in Code Composer
Studio for a class project, and it is so far not much better than random. I
was wondering if anyone had any suggestions on my current approach or knew
of a good reference on a basic signal processing algorithm. I am a beginner
to speech processing, so any advice would be greatly appreciated.
My current approach is to input a floating-point representation of a wav
file containing a single recorded word sampled at 4 kHz. I window it into
75 ms frames, and I remove any of these frames where the majority of the
speech values are a very small number (ie, to eliminate the frames that
occur before and after you start and stop speaking the word). I then
calculate and store the LPC coefficients for each of these frames.
I do this for approximately 20 different words, which will form the codebook
of possible words. Then I input the word to be recognized from a different
speaker, using the same method, and compare it to each of the words in the
codebook to find the best possible match. For each possible word, I take
the sum of the squares of the differences in the LPC coefficients for the
codebook word and word to be identified, in each of the 75 ms frames. I
take the word with the least total difference to be the match.
This approach is not accurately recognizing the speech inputs, and I would
very much appreciate any suggestions.
Thank you,

Gina Upperman


Reply by Gina Upperman November 26, 20052005-11-26
Hi All -
I am trying to make a simple speech recognition program in Code Composer
Studio for a class project, and it is so far not much better than random. I
was wondering if anyone had any suggestions on my current approach or knew
of a good reference on a basic signal processing algorithm. I am a beginner
to speech processing, so any advice would be greatly appreciated.
My current approach is to input a floating-point representation of a wav
file containing a single recorded word sampled at 4 kHz. I window it into
75 ms frames, and I remove any of these frames where the majority of the
speech values are a very small number (ie, to eliminate the frames that
occur before and after you start and stop speaking the word). I then
calculate and store the LPC coefficients for each of these frames.
I do this for approximately 20 different words, which will form the codebook
of possible words. Then I input the word to be recognized from a different
speaker, using the same method, and compare it to each of the words in the
codebook to find the best possible match. For each possible word, I take
the sum of the squares of the differences in the LPC coefficients for the
codebook word and word to be identified, in each of the 75 ms frames. I
take the word with the least total difference to be the match.
This approach is not accurately recognizing the speech inputs, and I would
very much appreciate any suggestions.
Thank you,

Gina Upperman