Enderman is very loud when it does it's buzzing noise, to the extent it hurts my ears.  This noise continues even if the enderman warps away (but stays in the general area)  This reproduces intermittently.  

REPRO:

Stand near enderman and hit it at least once.  Wait for enderman to make it's buzzing noise, Note that sound gets progressively louder to the extent it's uncomfortable.  Intermittent repro, may take a few tries to get it.