基于IIR滤波器和FIR滤波器的matlab仿真.zip

close all; clear all; [x, Fs] = audioread('male_speaker.wav'); plot(x) title('Speech Signal') ts=1/Fs; window_sec=0.020; num_samples=round(window_sec/ts); t = 0 : 1/Fs : num_samples/Fs; voice_start=31000; %from inspection of the signal x_voiced=x(voice_start:voice_start+num_samples); figure plot(t,x_voiced) axis([0 num_samples/Fs -(max(x_voiced)+.1) max(x_voiced)+.1]) title('Voiced Part of Speech') %determine lpc coefficients p_order=10; a_voiced=lpc(x_voiced,p_order); %----- %look at xcoor xcorr_lenght=num_samples/2; [auto_corr_voiced,lags] = xcorr(x_voiced,xcorr_lenght,'coeff'); figure stem(lags,auto_corr_voiced) title('Correlation Coeffiecent of Voiced Part of Speech') %----- %FFT method of modeling signal source, using num_sample as length of fft fft_len=num_samples; fft_voiced=fft(x_voiced, fft_len); y = linspace(0,Fs/2,fft_len/2); figure stem(y, abs(fft_voiced(1:length(fft_voiced)/2))) axis([0 1500 0 max(abs(fft_voiced))]) title('Fourier Transform of Voiced') %inverse fft to create signal source with smaller number of coefficents %picking 50 coef below. num_fft_coef=50; trun_fft_coef=[fft_voiced(1:num_fft_coef); zeros(length(fft_voiced)-num_fft_coef,1)]; voiced_signal_source=real(ifft(trun_fft_coef)); %this creates the time sequence %create estimate of speech signal using lpc filter and ifft sequence as the source estimated_voice=filter([0 -a_voiced(2:end)],1, voiced_signal_source); %pad with a zero so same length as original sequence estimated_voice=[0; estimated_voice]; figure plot(t,x_voiced) hold on plot(t,(estimated_voice), '-r') title('Comparison of Original Speech and FFT Recreated Speech with LPC order 10') %--------- %using dct method of modeling signal source voiced_dct_coef = dct(x_voiced,num_samples); %truncate the number of dct num_dct_coef=60; trun_dct_coef=[voiced_dct_coef(1:num_dct_coef); zeros(length(voiced_dct_coef)-num_dct_coef,1)]; %inverse dct (recreate voiced signal with smaller number of dct coefficents idct_voiced=idct(trun_dct_coef);%this creates the time sequence from dct %create estimate of speech signal using lpc filter and idct sequence as the %source estimated_voice_idct=filter([0 -a_voiced(2:end)],1, idct_voiced); %pad with a zero so same length estimated_voice_idct=[0; estimated_voice_idct]; figure plot(t,x_voiced) hold on plot(t,estimated_voice_idct, '-r') title('Comparison of Original Speech and DCT Recreated Speech with LPC order 10') %--- %write the files to disc %wavwrite(x_voiced,Fs,'original_speech') %wavwrite(estimated_voice_idct,Fs,'reconstructed_speech_idct') %wavplay(estimated_voice_idct,Fs)