www.pudn.com > 305-matlabCode.zip > mecho1_m.m

%PROJECT: AUDIO SIGNAL PROCESSING 
%IMPLEMENTATION OF MULTIPLE ECHO EFFECT IN THE AUDIO SIGNAL 
%mecho1 FUNCTION 
%PROJECT BY: 
 
function y = mecho1_m(); 
[x,fs,nbits]=wavread('wav_2.wav');%read in wav file 
xlen=length(x);%Calc. the number of samples in the file 
% the ratios for attenuation 
a0=0.9; 
a1=0.8; 
a2=0.7; 
%calculate no of samples for delay greater than 50 ms 
R=ceil(fs*120e-3); 
len=size(x)+3*R; 
y=zeros(1,len); 
% filter the signal 
x=x'; 
d0=[zeros(1,R) x zeros(1,2*R)]; d0=a0*d0; 
d1=[zeros(1,2*R) x zeros(1,R)];d1=a1*d1; 
d2=[zeros(1,3*R) x];d2=a2*d2; 
for i=1:1:R+1 
y(i) = x(i); 
end 
y=[x zeros(1,3*R)] + d0 +d1 +d2;