audio formats:

typical for 220a is .wav (also known in some software as RIFF), 
  other possibles: .aiff (Mac), .au (Sun), .snd (NeXT)

typical is 16bit, 48kHz resolution, 
  others are: 44.1kHz (CD consumer), or 96kHz, 24bit (pro standard)

typical is 1 - 8 channels
  someday we'll get to 100+

sox is a command-line program which converts most anything to anything
  for example, assume you have a mono, 22kHz file named oldsnd.wav
  and you want to go from mono to stereo and increase the sampling rate 
  all in one command

  type in a terminal
sox oldsnd.wav -c2 -r48000 newsnd.wav

more about sox by typing 
  man sox
  or 
  sox --help

_____________
we won't need audio compression for 220a, but compression formats are available
  Ogg Vorbis (open standard encode / decode)
  mp3 (decode, proprietary encode -- not supported)

for info on applications currently on the system that are compression savvy type:
  apropos vorbis
  apropos mp3
and then the man pages for the apps that you find, e.g., 
  man mpg123