Waxx
Major Contributor
I would not say that, but a familiar voice has a certain tonality that is easy to recognise if something is wrong, an other sound not. There was a time i bought and sold a lot of second hand speakers (selling often after fixing them) and then the voice test (next to listening to some reference tunes on it) was a crucial tool for me to see what i had in hands and what state it was in. Measuring in those circumstances is impossible, so I needed something else that worked. Like that i got some very good second hand speakers for very little money that i kept for various purposes.very right.
also: slam you door, record it. play it back. slam it again. (also knock on door....or perhaps eve better; (let someone) knock on the speaker itself)
record hand-claps: they sound unatural pretty fast if something is off.
record a thunderstorm. play it back and compare to the real event.