Vectors must be the same length with .wav file

Answer 1

[MaryD]

t = linspace(0, length(y)/fs,length(y));

I think you use linspace in wrong way. "y = linspace(x1,x2,n) generates n points. The spacing between the points is (x2-x1)/(n-1)."

try

t=0:length(y)/fs:length(y)