Chaotic noise (6)
I believe the answer is:
hubbub
'chaotic noise' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for hubbub that I've seen before include "Chaotic noise of crowd" , "General commotion" , "'Brouhaha, uproar (6)'" , "A lot of noise" , "Loud confused noise from many sources" .)