Stardust Makes Great Catch...Heads for Touchdown

Is there a microphone like device on board that records hits from
particles?
Anyway of knowing before we get it back if the particle catcher
actually caught anything? Or that it didn't get wiped out by a big
particle?

Yes, there is an instrument called the Dust Flux Monitor, that is mounted
on the front of the spacecraft to measures particle hits. The data
from that instrument indicates that Stardust had passed through two jets
when it flew by the comet.

Ron Baalke