Question on generating echo effect

How do I create a function that will add an echo effect to the audio signal? The function should take in the sound vector, sampling frequency, delay in seconds, and echo amplitude. The function should return a vector containing the echoed sound.

The function must:

(a) Take in the audio vector and sampling frequency, delay and echo gain.

(b) Convert the delay in seconds to number of samples: delaySamples = Fs * delay;

(c) Figure out a way to add a delayed version of the signal vector to the original audio vector: delaySamples tells you how many elements the offset needs to be. echoGain sets the amplitude of the echo signal (0.5 = 50% amplitude, 1 = 100% amplitude, 1.5 = 150% amplitude, etc.) to be added.

(d) Return the new version of your audio vector:

Then, play the new version of the audio vector.

What I have so far is:

function [audioVecEcho] = audioEcho(audioVec, Fs, delay, echoGain)

So far, this is what I have for the function:

function [eSound]=audioEcho( audioVec, Fs, delay,echoGain)

delaySamples= round(Fs * delay);

echoGain=echoGain*audioVec;

y=[audioVec,Fs];

eSound=y + [zeros(delaySamples-1, 1); y(delaySamples:end)];

end

It doesn't seem to work though. Please help me!

Answer 1

[Thiago Henrique Gomes Lobato]

Try this

function [eSound]=audioEcho( audioVec, Fs, delay,echoGain)

delaySamples= round(Fs * delay);
delayVec = zeros(size(audioVec));
delayVec(delaySamples:end,:) = audioVec(1:end-delaySamples+1,:);
eSound = audioVec + delayVec*echoGain;


end