Sound location is misplaced when spectating a mob.

I was testing spectating mode some more and I started to spectate silverfish.
I have 5.1 surround headset, and when silverfish made some noise, I heard the noise come from left. Then silverfish turned around and started to crawl into other direction, I heard noise come from right. Very strange.

I tested this bug too with my other stereo headset and it was barely not noticeable.