Y = auread('filename')
Y = auread('filename') reads the audio file in filename and converts the data from µ-law encoded bytes to a signal in the range -1 <= Y <= 1.
auread reads the data from the specified file as 8-bit, unsigned character data. The high-order bit is a sign bit, where 1 represents positive data and 0 represents negative data. The remaining seven bits represent signal magnitude, and are inverted (1's complement).
auwrite
(c) Copyright 1994 by The MathWorks, Inc.