csis01
Cool. I wouldn't know so I'll take your word for it.
I have also seen DJs in clubs and bars literally hold up their DJ headphones and yell into the headphone speaker and have their voice come out the main speakers and make an announcement. The voice was very bassy and muddy, but intelligible. I suppose they might have temporarily plugged the headphone into the microphone input of the mixing board. But point being that the speaker can pick up environment sounds and feed it back into the cable. But having the amplification/dac component capture incoming sound is a different story.