a sound file specified by the string aufile.
The data should be arranged with one channel per column. Amplitude
values outside the range [-1,+1] are clipped prior
to writing. auwrite supports multichannel data
for 8-bit mu-law and 8- and 16-bit linear formats.
the sample rate of the data in Hertz.
the number of bits in the encoder. Allowable settings are N =
8 and N = 16.
selection of the encoding method, which can be either 'mu' or 'linear'.
Note that mu-law files must be 8-bit. By default, method =