Also called acoustic regeneration. The mechanical coupling of a portion of the sound waves from the output of an audio amplifying system to a preceding part or input circuit (such as a microphone) in the system. When excessive, acoustic feedback produces a howling sound in the speaker.
"Wanted to thank you for the (again) terrific job you've done. The only time I have for music is in my car so it's nice to re-acquaint myself with some of my old favorites!"
