As many are aware if you tap backwards you can spam your mounts sound but there is a delay in the time between sounds.
However since the patch If you mouse turn on the spot while spamming the mountspecial (spacebar) button you will spam the mount's sound.
Example:
I'm on a Nightsaber, I turn on the spot slowly using my mouse and spam the spacebar and the Nightsaber spam roars.
Excellent for annoying other players.