You must understand that you've given us fairly little to work with. No specifics on hardware, no logs, no EmulationStation version, no real source for the error, etc. It's kind of why the warning before posting exists: the more info you provide, the more likely you are to get an attempt at an answer.
Let me try something: do you hear audio in everything? Are you using videos? When do you get that error - in an emulator? In EmulationStation?
Either way, in the sound menu from EmulationStation try to change the audio device one by one, restart and see if the error persists.
And yes, I suppose if nobody answered it's likely nobody has had that error.