Disturbing sounds perhaps not at all lacking in watts (5)
I believe the answer is:
noise
'disturbing sounds perhaps' is the definition.
(noise can mean disturbing sounds)
'not at all lacking in watts' is the wordplay.
'not at all' becomes 'nowise' (nowise means 'in no way').
'lacking in' is a deletion indicator.
'watts' becomes 'W'.
'nowise' with 'w' removed is 'NOISE'.
(Other definitions for noise that I've seen before include "Confused sounds" , "Clatter" , "Unwanted sound" , "Hubbub" , "Rumour" .)