AWOL:
I doubt 3-4 KHz would be sufficient for very low quality speech,
Why do you think that?
3kHz has been standard telephony bandwidth for decades.
Ah right nevermind, I mistakenly assumed that low quality CDs are 22.05 kHz and 3kHz would be totally unintelligible. Thank you.
This does make things a bit easier I guess. Would I be able to sample from the microphone via ADC, and play it to a speaker through DAC?