got

Code/frequencySpectrum.m

@@ -1,4 +1,4 @@
-function [power, duration] = frequencySpectrum(signal, fs, pad, plot)
+function [power, duration] = frequencySpectrum(signal, fs, pad, verbose, rangefr)
 %%%%%%%%%%%%%%%%%%
 %function power = frequencySpectrum(signal, fs, pad)
 %
@@ -31,7 +31,10 @@ power = abs(y).^2/n;    % power of the DFT
 
 [val, ind] = max(power); % find the mx value of DFT and its index
 
-if (plot)
+rangemin = rangefr(1);
+rangemax = rangefr(2);
+
+if (verbose)
   % plots
   figure;
 
@@ -53,9 +56,13 @@ if (plot)
   plot(f,power, 'r');
   xlabel('Frequency (Hz)')
   ylabel('Power (a.u.)')
+  xlim([rangemin rangemax]);
 
   subplot(1,3,3) % log frequency plot
-  plot(f,10*log10(power/power(ind)));
+  power_db = 10*log10(power/power(ind));
+  plot(f, power_db);
   xlabel('Frequency (Hz)')
   ylabel('Power (dB)')
+  xlim([rangemin rangemax]);
+
 end

Code/speech_analysis.m

@@ -7,13 +7,18 @@ pkg load signal
 #xlabel('Time(s)');
 #ylabel('Signal Amplitude (normalized unit)');
 
+
 #audiowrite("modifiedmodulator.wav",signal,Fs/2);
-[signal, Fs] = audioread("modifiedmodulator.wav");
+[signal, Fs] = audioread("Sound/modulator22.wav");
 t=0:1/Fs:length(signal)/Fs - 1/Fs;
-#figure; % Create a new figure
-#plot(tt,signall);
-#xlabel('Time(s)');
-#ylabel('Signal Amplitude (normalized unit)');
+#player=audioplayer(signal, Fs, 8)
+#play(player);
+##figure; % Create a new figure
+##plot(t,signal);
+##xlabel('Time(s)');
+##ylabel('Signal Amplitude (normalized unit)');
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 % Parameters for measurements
 num_measurements = 100; % Number of measurements
@@ -23,12 +28,12 @@ durations_fft = zeros(1, num_measurements);
 for i = 1:num_measurements
     % Measure time taken for DFT
     tic;
-    [power_dft, duration_dft] = frequencySpectrum(signal, Fs, false, false);
+    [power_dft, duration_dft] = frequencySpectrum(signal, Fs, false, false, [100 2700]);
     durations_dft(i) = duration_dft;
 
     % Measure time taken for FFT with padding
     tic;
-    [power_fft, duration_fft] = frequencySpectrum(signal, Fs, true, false);
+    [power_fft, duration_fft] = frequencySpectrum(signal, Fs, true, false, [100 2700]);
     durations_fft(i) = duration_fft;
 end
 
@@ -45,6 +50,48 @@ fprintf('\n');
 fprintf('Average duration for FFT (with padding): %f seconds\n', avg_duration_fft);
 fprintf('Standard deviation for FFT (with padding): %f seconds\n', std_dev_fft);
 
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%Searching for formants without low pass filter
+
+##start_time = 0.7; % start time in seconds
+##end_time = 1.3; % end time in seconds
+##
+##start_index = round(start_time * Fs) + 1; % start index
+##end_index = round(end_time * Fs) + 1; % end index
+##
+##cropped_signal = signal(start_index:end_index); % cropped signal
+##
+##[power_dft, duration_dft] = frequencySpectrum(cropped_signal, Fs, false, true, [0 160]);
+
+#spectrogram(signal, Fs, 5, 30);
+#spectrogram(signal, Fs, 5, 5);
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%formants with low pass filter
+
+N=8;
+fc=2700;
+[b,a]= butter(N,fc/(Fs/2));
+freqz(b,a);
+
+signal_filtered=filter(b,a,signal);
+
+start_time = 0.75; % start time in seconds
+end_time = 0.95; % end time in seconds
+
+start_index = round(start_time * Fs) + 1; % start index
+end_index = round(end_time * Fs) + 1; % end index
+
+cropped_signal = signal_filtered(start_index:end_index); % cropped signal
+
+[power_dft, duration_dft] = frequencySpectrum(cropped_signal, Fs, false, true, [0 2700]);
+
+
+
+
+
+
+
 
 
 

fir_iir.m

@@ -0,0 +1,67 @@
+
+clc
+clear all
+close all
+
+pkg load signal
+
+samplingFreq = 500; % in Hz
+N = samplingFreq; % number of samples for a 1s buffer of data
+Nfir=7;  % filter order
+cutOffFrequency=10;  % cut-off frequency
+ 
+% sampling weighted window (hanning)
+whann = window(@hanning,Nfir);
+ 
+% Coefficients estimation using the inverse of the Fourier transform and  truncation of the impulse response
+n=0:1:(Nfir-1);
+h=2*cutOffFrequency*sinc(2*(n-(Nfir-1)/2)*cutOffFrequency/samplingFreq)/samplingFreq; % Impulse response of the filter 
+ 
+hhann=(h.').*whann;                % Weighting h by the Hanning window 
+hhann=hhann/sum(hhann);            %  Normalisation of the sum od the coeffs to be 1
+figure
+freqz(hhann,1,N,samplingFreq);   % Frequency response of the impulse response weighted by the Hanning window
+title('FIR Low-pass, order 6');
+subplot(2,1,1)
+ylim([-100 20])
+	
+[B, A] = butter(Nfir,  cutOffFrequency/(samplingFreq/2));
+figure;
+freqz(B,A,N,samplingFreq)
+title('IIR Low-pass, order 6');
+subplot(2,1,1)
+ylim([-100 20])
+
+[Bc, Ac] = cheby1(Nfir,  10, cutOffFrequency/(samplingFreq/2));
+figure;
+freqz(Bc,Ac,N,samplingFreq)
+title('IIR Low-pass, order 6');
+subplot(2,1,1)
+ylim([-100 20])
+
+
+
+Z=roots(B)         % Zeros of the transfer function
+P=roots(A)         % Poles  of the transfer function
+
+% Representation of zeros/poles in the complex plan
+figure
+zplane(Z,P)  % Draw zeros and poles
+title ('Zeros and poles of the transfer function of the IIR filter')
+legend('zeros','poles')
+grid on
+
+% Representations of the impulse response of the IIR filter
+figure
+impz(B,A)    % Draw the impulse response
+title ('Impulse response of the IIR filter')
+xlabel('Sample (n)')
+grid on
+
+% Representations of the impulse response of the FIR filter
+figure
+impz(hhann,1)    % Draw the impulse response
+title ('Impulse response of the FIR filter')
+xlabel('Sample (n)')
+grid on
+