Every once-and-a-while, I notice that music (in any format) played on my Mac doesn't sound very good. The first time this happened, I couldn't figure out why, and someone here (or it may have been Apple Care, I can't recall) walked me through a troubleshooting process that ended when it was discovered that, in Audio MIDI Setup, the Audio Output Format settings had somehow shifted from the standard 44100.0 Hz, 2 channel, to 32000 Hz, 1-channel.

It was easy enough to change these back to the proper settings, but this has happened about 7 or 8 times now, and it's annoying. Is there some reason that my Audio Output changes settings on its own? How can I prevent this from happening in the future? I can think of nothing that would correspond to this change – I have not been unplugging or reconnecting any components or changing any other settings (other than the volume control on the keyboard or in iTunes).

I am using O/S 10.4.8 (although the problem has occurred in previous systems) on a Dual-1.25GHz G4 with plenty of RAM. My sound output is through a Griffin iMic. I have had no other problems other than the usual occasional crashes.

Keith, I'm betting on a piece of software changing the setting. You might see if you can spot a pattern. Could be just about anything, from a game to something with audio reminders.