Noisy mass on supporting structure (5)
I believe the answer is:
pylon
'structure' is the definition.
(pylon is a kind of structure)
'noisy mass on supporting' is the wordplay.
I cannot really understand how this works, but
'on' is within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for pylon that I've seen before include "Power cable support" , "Tower or tall post" , "Power cables supporter" , "power supplier?" , "it may mark a turning point" .)