very good
I liked it i myself have just started toying with using the microphone inputto controll things in flash and have a few ideas for how to incorporate it into small games.
I liked this the only thing i would sugest is that if you have a really quiet noise in the background it sets of the trumpet sounds i thik if you could get rid of that by settining the varible that controlls the trumpet as the activity level but then saetting the varible to 0 if the activity level is bellow a certain point
apart from that i really liked it nice work