Matlab code:
clc;clear;close all;
Fs = 16000; %Sampling frequency
Fco = 500; %Cutoff frequency
order = 4;
[b, a] = butter(order, Fco/(Fs/2), 'low');
%Generate white noise
x=2*rand(16000,1)-1;
y = filter(b, a, x); %get time domain result
spectrogram(x,[],[],[],Fs,'yaxis');colormap hot;title('x');figure
spectrogram(y,[],[],[],Fs,'yaxis');colormap hot;title('y');
Result:
References:
Divide a speech utterance into 3 bands
Apply a LPF in the time and frequency using filter() and freqz()
