I'm not really familiar with condensor mics, but something doesn't look right to me(actually, several things don't look right). Why is the mic connected between the base of Q1 and the positive supply? Wouldn't you want it connected between base and common? Your screen shots don't tell us what the simulation output looks like. For starters, What does the collector of Q1 look like with respect to the mic output? I don't think that the trigger input to the 555 is proper, either; I think you may need a pull-up there.