clear all 
close all
pkg load signal
[x, fs] = audioread('modulator22.wav');
sound(x, fs);
y = decimate(x, 5);
new_fs = fs/5;
display(new_fs);
audiowrite('decimated.wav', y, new_fs);
spectrogram(x,fs,5,30);
title('original');
spectrogram(y,fs,5,30);
title('decimato');
sound(y, new_fs);