[thrtythreeforty]

This is great. Missed opportunity for a low-pass RC filter on the speaker circuit - if you know you're driving an 8kHz sample rate, you can design your filter with that cutoff, and it'll sound way better (it'll get rid of the buzzy quality).

[kragen]

This may be essential if you're connecting it to an audio amplifier. I learned this the hard way by burning out someone else's very expensive tweeters with 31.25kHz PWM.