How to add white noise to speech signal (matlab)

First make the lengths of the two signals the same

Suppose the lengths of the two signals x and y are M, N, Mgt; N,

Method 1 : Resample the short signal y (length N) into length M

y = resample(y, M, N);

Method 2: Resample the long signal x (length M) Resample to length N

x = resample(x, N, M);