Multiplication of sound and sinusoidal signal

clc;
[a,Fs]=audioread("music.wav");
%sound(a,Fs);
si=size(a);
t=si/Fs;
t2=0:1/Fs:1;
f=15000;
signal=sin(2*pi*f*t2);
A=a';
K=A*signal;


When i try to multply i got an error . idont know what to do ?

[Jan]

If you get an error message and want the forum to help you, it is useful to post a copy of the complete message. It is easier to solve a problem than to guess, what the problem is.

Note that size(a) replies a vector. This is not a problem here, because t is not used anywhere.

Answer 1

[Omer Yasin Birey]

The problem here is you take the t2 until 1 second, when your sound lasts more (or less) than 1 second

t2=0:1/Fs:1;

However it must last until the duration not until 1. Therefore, change this line with

t2=0:1/Fs:duration;

And also I believe you want to do element wise multiplication so put a dot before the multiplication sign.

clc;
[a,Fs]=audioread('music.wav');
duration = length(a)./Fs;
si=size(a);
t=si/Fs;
t2=0:1/Fs:duration-1/Fs;
f=15000;
signal=sin(2*pi*f*t2);
A=a';
K=A.*signal;

[ali okumus]

Thank you very much .I really appreciated your help .it worked for me .

Answer 2

[Jan]

I guess, you want this:

[a, Fs] = audioread('music.wav');
len     = size(a, 1);
t       = (0:len - 1) / FS;  % time in seconds
freq    = 15000;
signal  = sin(2 * pi * freq * t);
result  = a .* signal.';

This multiplies even stereo signals, but you need >= R2016b for the auto-expanding. Please ask, if you use an older Matlab version.

[Oswaldo Colin Martinez]

Thankyou! After a few years, this post has saved me.

Answer 3

[ali okumus]

Dear friends

I really appreciate your concerns .i got my problem solved. thank you .