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Subject: Re: How to remove white noise from wav audio files
Date: Sat, 22 Nov 2008 07:28:04 +0000 (UTC)
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JOE <joemwangii@gmail.com> wrote in message <18667858.1217186063014.JavaMail.jakarta@nitrogen.mathforum.org>...
> Hi!I have been making a speaker verification system using Matlab.Unfortunately,when I record wav audio clips via a microphone,white noise is present in the wav files.
> 
> How do I remove the white noise to enable a more accurate speaker verification system?
> 
> My code for reading the wav file is as below
> 
> [s,fs]=wavread('train\joe.wav');
> 
> I was hoping to remove the white noise from the amplitude values (s) such that the filtered signal becomes one of the input parameters in my Mel-Frequency Cepstrum Co-efficients as shown below
> 
> v = mfcc(s, fs); where s is the filtered signal.
> 
> Please help me and I shall be infinitely grateful.Thanks in advance.

The best you can do i guess is to apply a lowpass or bandpass filter to your signal, keeping only the frequency range where the signal of interest is. Unless you have any means of predicting the signal of interest, you can not remove white noise when the spectra of noise and signal overlaps.

When filtering, take a look at the filtfilt function, since it preserves the phase of your original signal.

/JC