What does Byaaah! byaaah mean?

Byaaah! byaaah meaning in Urban Dictionary

The catchphrase of Dave Chappelle as Howard Dean. It Offers punching your right hand into top-right about 45°. Dave himself in addition does/says this at sexual orgasm (orgasm). dave chappelles funniest line ever. based on howard deans message wherein he tends to make a retarted donkey-sounding sound