audioProcessingInMatlabSimulink

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About Me Experiences: 1993-1995: The MathWorks, Inc. 1995-now: CS Dept., Tsing Hua Univ., Taiwan

Research interests Speech/Audio Signal Processing, Fuzzy Logic, Neural Networks, Pattern Recognition, Biometric Identification, Document Classification, Webbased Technologies

Programming languages: MATLAB, C, JavaScript, VBScript, Perl«

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Outline Wave file manipulation Reading, writing, recording ...

Time-domain processing Delay, filtering, sptools «

Frequency-domain processing Spectrogram

Pitch determination Auto-correlation, SIFT, AMDF, HPS ...

Others Formant estimation, speech coding 3

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Toolbox/Blockset Used MATLAB Simulink Signal Processing Toolbox DSP Blockset

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MATLAB Primer Before you start, you need to get familiar with MATLAB. Please read ³MATLAB Primer´ at the following page: http://neural.cs.nthu.edu.tw/jang/demo/demoDownload. asp Exercise: 1. Please plot two curves y=sin(2*t) and y=cos(3*t) in the same figure. 2. Please plot x vs. y where x=sin(2*t) and y=cos(3*t).

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To Read a Wave File To read a MS .wav file (PCM format only): wavread â
 


   

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If the wav file is stereo, y will be a two-column matrix.

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To Read a Wav File    

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Exercise€  ' !    () * +%#,%-. (/) &   ! $$&  $&  () $$&  ' ! 0$!    ( ) ;

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Solution to the Previous Exercise wavRead02.m: [y, fs] = wavread(µflanger.wav¶); subplot(2,1,1), plot((1:length(y))/fs, y(:,1)); subplot(2,1,2), plot((1:length(y))/fs, y(:,2));

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To Play Wav Files To play sound using Windows audio output device: wavplay, sound, soundsc ââ  ââ  1â$.  0$2  $ ââ  1â$.  $2  $ &â  &$  &$ ! &

Example (wavPlay01.m)€

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To Read/Play Using DSP Blocks To read/play sound using DSP Blockset:  ' -$2" ' &$"´ 3 ´   ' -$2" ' 2"# 3  $

Example:

Frame-based operation!

Exercise: 4    !  10

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Solution Solution to the previous exercise: slWavFilePlay01.mdl

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To Write a Wave File To write MS wave files: wavwrite  â      ( ) &  5  6 (â) & !  $&    % & & &  0  $ 

Example (wavWrite01.m)€

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Exercise€ #â & !    12

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To Record a Wave File To record wave files:  * ! $  &  â & 3 9'  * ($) & +%#,%- : * (´ 3  $) & & 2 & ( ' -$2"'  $ $ ;