Digital Signal Processing Systems, Basic Filtering Types, and Digital Filter Realizations - Digital Signal Processing: Fundamentals and Applications - page 202

Original speech

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Pr e -empha s ized spe e ch

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FIGURE 6.31

Amplitude spectral plots for the original speech and pre-emphasized speech.

title( Speech: We lost the golden chain. )

' '

subplot(2,1,2),plot(y);grid
ylabel(

Filtered samples )

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xlabel( Number of samples );

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title( Preemphasized speech. )

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figure(3);
N ¼ length(speech); % Length of speech

Axk ¼ abs(fft(speech.*hamming(N) ' ))/N; % Two-sided spectrum of speech

Ayk ¼ abs(fft(y.*hamming(N) ' ))/N; % Two-sided spectrum of pre-emphasized speech

f ¼ [0:N/2]*fs/N;
Axk(2:N) ¼ 2*Axk(2:N); % Get one-sided spectrum of speech

Ayk(2:N) ¼ 2*Ayk(2:N); % Get one-sided spectrum of filtered speech

subplot(2,1,1),plot(f,Axk(1:N/2 þ 1));grid
ylabel( ' Amplitude spectrum Ak ' )
title( ' Original speech ' );
subplot(2,1,2),plot(f,Ayk(1:N/2 þ 1));grid
ylabel( ' Amplitude spectrum Ak ' )
xlabel( ' Frequency (Hz) ' );
title( ' Preemphasized speech ' );
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