Swimmer with the deep deep voice (3,4)
I believe the answer is:
sea bass
'swimmer' is the definition.
(sea bass is a kind of fish)
'with the deep deep voice' is the wordplay.
'with' is a charade indicator (letters next to each other).
'the deep' becomes 'sea' (the deep can mean the sea).
'deep voice' becomes 'bass' (I've seen this before).
'sea'+'bass' is 'SEA-BASS'.
(Other definitions for sea bass that I've seen before include "Marine food fish" , "Edible marine fish" , "one showing off plenty of scales" , "Saltwater fish" .)