How can i add echo to a signal

I want to add echo to a signal

load handel

how do i add echo to this

[Walter Roberson]

Do you want echo or reverb?

[Ijeoma Madu]

echo

[Henry Solderless]

also if you want you can define the vector (1:size)

Answer 1

[Vieniava]

load handel;
echo_delay   = 0.5;                    % in seconds
echo_delay_s = round(echo_delay*Fs);   % delay in samples
echo_gain    = 0.1;                    % to control a linear gain of an echo
y_echoed     = y + [zeros(echo_delay_s-1, 1); y(echo_delay_s:end)];

[Walter Roberson]

This is not echo in the traditional sense. In addition to the delay, echo typically has a different phase, and usually consists of several copies rather than just one, as echo is from a surface (or set of surfaces at different distances) rather than from a point.

This code is closer to reverb with a lot of dampening.

[Perturabo]

I have to make an echo generator too but the instructions say nothing about the phase difference; Just input, Fs,delay and gain. When i test it on various inputs it just says

Variable output must be of size [10820 1]. It is currently of size [73113 1]. Check where the variable is assigned a value

When using the above function.

[Priyamvada Shankar]

@Perturabo please tell me, if you get the correct code.. I'm too stuck in this situation..so please help

Answer 2

[Vieniava]

For example: to add an echo after 1s (with amplitude=0.1, phase=pi/3.5) and echo after 1.5 seconds (with a=0.5 and phase=1.2*pi) you can use the following code:

echo_vector=[1                  zeros(1,Fs)     ... 
             0.1*exp(1i*pi/3.5) zeros(1,1.5*Fs) ... 
             0.5*exp(1i*1.2*pi)                   ];
yecho=real(conv(y,echo_vector);

Using echo_vector that way you have full control of an echo creation.

Answer 3

[Julia Esposito]

How can I load an audio file and use a GUI to make it echo?