Using $PROMPT_COMMAND to beep depending on success/failure

[Linux for blind general discussion]

Okay, I've installed beep and I've tried playing around with trying to
get it to play a tone for five seconds, but it's not producing any
sound.

I'm assuming the problem is with whatever it determines the default
playback device is, but I have no idea what to feed to the -e option
to specify a sound device.

Any idea what's going on?