Created wave files - getting clicking noises

Hi,

I'm trying to create some wavefiles in matlab, and everything seems to be going well except that I'm getting weird clicking sounds at the beginning and end of the wave. Anyone know why this might be?

%%

sf = 22050;                    % sample frequency (Hz)====== sampling rate
d = .5;                       % duration (s)=========duration
n = sf * d;                    % number of samples
silence= zeros(1,n);
% set carrier
cf = 378;                     % carrier frequency (Hz)
c = (1:n) / sf;                % carrier data preparation
c = 2 * pi * cf * c;

% set modulator
mf = 3;                        % modulator frequency (Hz)===== modulation frequency
mi = 150;                      % modulator index============= what we call modulation depth
m = (1:n) / sf;                % modulator data preparation
m = mi * cos(2 * pi * mf * m); % sinusoidal modulation

% frequency modulation
s = sin(c + m);                % frequency modulation
s=[silence s silence];

% sound presentation
sound(s, sf);                  % sound presentation
pause(d + 0.5);                % wating for sound end

wavwrite(s,sf,'fmsound.wav')

[Walter Roberson]

... beginning and the end. Possibly exactly matching your "silence", or is it more than 1/2 second?

Answer 1

[Jan]

Correct, there is a click at the start and the end of the sound. The surrounding silence is not the problem. It's only the sudden start and end of the signal, which causes the clicks. You can draw the signal and use the zoom tool to see the sharp edges.

plot(s)

[AMB]

Hi

Consider the following example playing sig produces a click but playing y does not. y has a weight applied which gets rid of the click

fs = 2000; t = 0 : 1/fs : 0.3; sig = 0.7 * chirp(t,0,0.3,10000); nS = length(sig); w = .5*(1 - cos(2*pi*(1:nS)/(nS+1))); y = w.*sig; sound(sig,fs,8) pause(1) sound(y,fs,8) plot(t,sig,t,y)

V/r

amb