info = audioinfo('1.mp3');
[y,Fs] = audioread('1.mp3');
Let's say that 1.mp3 is a stereo (i.e., two channel) audio file that is 10 seconds long and has a sampling frequency of 44,100Hz. You can tell this from the info structure that you created with audioinfo(). In this case, Fs will equal 44100 and y will be a 441000x2 single-precision matrix (44100Hz*10sec = 441000samples). Each row of y will correspond to a particular sample and each column will correspond to one of the audio channels. For an mp3 file, the data range of y is -1.0 to +1.0. For other types of files, you can check the documentation by typing doc audioread into MATLAB.
