> While speakers can certainly be used as microphones, I doubt they'd be connected to an ADC so probably won't be useful
In most modern PCs with two audio jacks software will ask you what kind of device you just connected and reconfigure the sound chip to treat it as input or output. I wouldn't be surprised if clever software was able to convince Apple hardware to treat the built in speaker as a microphone.
In most modern PCs with two audio jacks software will ask you what kind of device you just connected and reconfigure the sound chip to treat it as input or output. I wouldn't be surprised if clever software was able to convince Apple hardware to treat the built in speaker as a microphone.