noiseReduction.m

% Matlab 2015 Code Template
clc;
clear all;
close all;
%load noisy speech
[noisy,Fs] = audioread('path to noisy.wav file');

% plot the noisy speech in time domain. xlabel: Time in seconds


% plot the spectra of Noisy speech . xlabel: Frequency in Hz
L = length(noisy);
NFFT = 2^nextpow2(L);
NOISY = fft(noisy, NFFT )/L;

% design the FIR (or IIR) filter based on the observation from the spectral plot. 
h_n = fir1(order, cutoff) ;% LP, BP,HP,BS, Multi Band pass, Multi band stop

%plot the magnitude response of the filter


%DO filtering
filtered = filter(h_n,1,noisy);

% plot the spectra of filtered signal


% play the filtered signal, see if there is some reduction of noise contribution
sound(filtered,Fs)

% if it doesnt sound good, change the filter

% if you feel some improvements
audiowrite('name_rollnumber.wav',filtered,FS)