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Lab_2_Speech_Processing
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Adding comments to the speech_analysis

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Mattis ROELLINGER 2024-03-28 14:09:20 +01:00
parent aaec5b54fa
commit 4cfaf94544
1 changed files with 18 additions and 3 deletions
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21
speech_analysis.m
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@ -1,42 +1,56 @@
%loading the signal library in octave
pkg load signal
clear all
close all
%reading of the orignial signal in data
[y,fs]=audioread('./data/modulator22.wav');
%calculation of the time from the sampling frequency
t=0:1/fs:length(y)/fs-1/fs;
%showing the original signal
##figure;
##set(gcf, 'name','Signal of origin');
##plot(t,y);
##xlabel('time(s)');
##ylabel('amplitude(n.u.');
%save a speed down version of the original signal
audiowrite('./data/modulator22_speedown.wav', y , fs/2);
%save the speed down version's signal and sampling frequency and calculate it's new time duration
[y_speedown,fs_speedown]=audioread('./data/modulator22_speedown.wav');
t_speedown=0:1/fs_speedown:length(y_speedown)/fs_speedown-1/fs_speedown;
%showing the speed down version's signal
##figure;
##set(gcf, 'name','Speed down of the signal of origin');
##plot(t_speedown,y_speedown);
##xlabel('time(s)');
##ylabel('amplitude(n.u.');
%Apply the DFT(flase) and FFT(true) to the speed down signal
%frequencySpectrum(y_speedown, fs_speedown, false);
%frequencySpectrum(y_speedown, fs_speedown, true);
%Illustrate the spectogram of the speed down version at 2 windows values (1 for a precise frequency read and 1 for a precise time domain)
%spectrogram(y_speedown, fs_speedown, 5, 30);
%spectrogram(y_speedown, fs_speedown, 5, 5);
%Lowering the sampling frequency using the downsample() function
##y_downsampled = downsample(y, 2);
##fs_downsample = fs/2;
##audiowrite('./data/modulator22_downsample.wav', y_downsampled , fs_downsample);
##t_downsample=0:1/fs_downsample:length(y_downsampled)/fs_downsample-1/fs_downsample;
%Lowering again the sampling frequency but with the decimate() function (applying a LP filter at the start )
##y_decimated = decimate(y, 2);
##fs_decimate = fs/2;
##audiowrite('./data/modulator22_decimate.wav', y_decimated , fs_decimate);
##t_decimate=0:1/fs_decimate:length(y_decimated)/fs_decimate-1/fs_decimate;
##
%Comparing them both on the same graph to see the effect of the LP filter on the signal itself
##figure;
##set(gcf, 'name','Decimate vs Downsample');
##title('Decimate vs Downsample');
@ -46,11 +60,12 @@ t_speedown=0:1/fs_speedown:length(y_speedown)/fs_speedown-1/fs_speedown;
##xlabel('time(s)');
##ylabel('amplitude(n.u)');
##legend('downsample()','decimate()',"location","southeastoutside");
##
%Illustrating them with their frequencySpectrum to see the effect of the LP filter
##frequencySpectrum(y_decimated, fs_decimate, true);
##frequencySpectrum(y_downsampled, fs_downsample, true);
%%%FILTER IMPLEMENTATION %%%%
%%%IIR and FIR LP FILTER IMPLEMENTATION %%%%
%creating a low pass filter FIR
N=30;
fc=1000;