adc~ has no signal when monitored with [env~] or [pvu~] --> [vu].

The internal microphone works. Audio drivers on Pd are set to take Built in microphone 2 channels. Audio and Midi drivers (on a Mac) is set to use internal microphone. I've used system preferences to test/playback mic input.

Other sounds work in Pd. DSP is on/computing. I tried listening for anything despite the visual showing that it wasn't working -- with headphones. I'm at a loss. Any help here is appreciated.

@jermain If you have another soundcard connected then possibly the microphone is not connected to the audio pins that Pd has been told (as it starts) are the microphone pins.
However, someone reported the same problem on Reddit (also for osx) a couple of years ago and found that uninstalling and reinstalling Pd fixed the issue.
David.