Do you mean that the sound seems unclear all the time?
I've also had some problems with sound on my FreeBSD 5.3-STABLE, but a
different kind of. Sometimes I hear crakings while playing mp3 files with
XMMS, although my computer's load is very low. I use "snd_emu10k1" sound
module as you do with a Creative Sound Blaster Live! 5.1.