Oh sure, I bring a little mini-speaker in to use when no one is around.
This thing has given me more value than probably anything I've ever bought. Good sound quality, completely portable, no batteries, and totally indestructible (in my experience).
You can also pick up one of these for around 15$ If your external speaker isnt loud enough. I've used one before, they work well and are small enough to hardly notice while in your goggle pocket.