/diy/ - Do It Yourself

I need advice on a matter. This should be simple, but I'm too retarded to piece this together. Anyways, I have a microcontroller outputting a sound effect that lasts for 2 seconds. I attached the output of the uC to a NPN for amplification (yes, I am aware this heats up the BJT, but I don't care due to how little this thing is going to run). But my main problem is that whenever the sound turns on, I hear this "thud" or "pop" sound before the sounds gets played and after the sound finishes (the sound itself plays just fine). I think it has something to do with influx and sudden switching, but I'm not sure what I can do to dampen or eliminate it.