y = mu2lin(mu) converts mu,
a mu-law encoded 8-bit audio signal with amplitudes in the range [0,255],
to a linear audio signal with amplitudes in the range
[-s,s], where
s = 8031/8192 ≅ 0.9803. The input argument
mu is often obtained using fread(...,"uchar") to
read byte-encoded audio files.
