trying the last part

speech_analysis.m

@@ -1,5 +1,39 @@
 [y,Fs] = audioread("modulator22.wav");
+#y = y(1.95*Fs:2.05*Fs)
+% n between 1 an d 1.1
+% u between 1.45 and 1.6
+% i between 1.95 and 2.05
+
 t = (0:length(y)-1)/Fs;
-plot(t, y);
-xlabel("Timee (s)");
-ylabel("Amplitude");
+%[pwr, dur] = frequencySpectrum(y, Fs, 0);
+%xlabel("Timee (s)");
+%ylabel("Amplitude");
+#spectrogram(y,Fs,5,5);
+
+Factor_of_reduction = 2;
+y_down = downsample(y,Factor_of_reduction);
+y_decimate = decimate(y,Factor_of_reduction);
+audiowrite("modulator_new.wav", y_down, Fs/Factor_of_reduction);
+
+%plot (t,y,'b')
+%hold on
+%t2 = (0:length(y_down)-1)/(Fs/Factor_of_reduction);
+%plot (t2,y_down,'r')
+%t3 = (0:length(y_decimate)-1)/(Fs/Factor_of_reduction);
+
+%plot (t3,y_decimate,'g');
+Fc = 1000;
+
+[b] = fir1 (30,2*Fc/Fs);
+y_b = filter(b,1,y);
+
+[a,c] = butter(8,2*Fc/Fs);
+y_ac = filter(a,c,y);
+
+plot (t,y_b);
+hold on;
+plot (t,y_ac,'r');
+
+freqz(a,c);
+freqz(b,1);
+

vocoder.m

@@ -0,0 +1,16 @@
+pkg load signal
+
+modfile = 'modulator22.wav';
+carfile = 'white_periodic.wav';
+outfile = 'vocodedsound.wav'
+[modul, sr1] = audioread(modfile);
+[carrier, sr2] = audioread(carfile);
+if sr1~=sr2, disp('your sampling rates dont match'); end
+% the chanvovoder function isn't availiable on Octave and i am not able to find an equivalent function
+
+y = chanvocoder(carrier, modul, 512, 16, .2);
+audiowrite(y,sr1,16,outfile)
+
+subplot()
+
+%% on the same figure temporal variation, carrier and output