We hear a campanologist helps with the washing (7)
I believe the answer is:
wringer
'helps with the washing' is the definition.
I can't tell whether this definition defines the answer.
'we hear a campanologist' is the wordplay.
'we hear' indicates a 'sounds like' (homophone) clue.
'a campanologist' becomes 'ringer' (I've seen this before).
'ringer' sounds like 'WRINGER'.
Can you help me to learn more?
(Other definitions for wringer that I've seen before include "trouble when put through this?" , "Kitchen appliance" , "Old clothes dryer" , "A mangle" , "Old-fashioned clothes dryer" .)