Noisy one, this supporter? (3)
I believe the answer is:
fan
'this supporter?' is the definition.
(fan is a kind of supporter)
'noisy one' is the wordplay.
'noisy' becomes 'f'.
'one' becomes 'an' (I've seen this in other clues**).
'f'+'an'='FAN'
(Other definitions for fan that I've seen before include "Devoted admirer or air cooler" , "Zealot" , "Cooling device for devoted follower?" , "Spanish women wave it to cool themselves" , "Lady Windermere's - -" .)