Checking for device availability before actually acquiring a stream would just create a race condition. The usual advice is to not mess with the sound preferences unless you're willing to have a disruption in output (at least this is better than it used to be, when any preference change caused the streams to be restarted). I'm tempted to mark this as wontfix as per above, but it is something that could be fixed (we could attempt to more precisely open and close streams, maybe) with a good amount of effort. Although even then if you were trying to add a mic input on a card that was outputting, you'd get a disruption in audio. On Sat, Dec 24, 2011 at 9:50 PM, RJ Ryan