Take advantage of sound sheep (4)
I believe the answer is:
ewes
'sheep' is the definition.
(a ewe is a female sheep)
'take advantage of sound' is the wordplay.
'take advantage' becomes 'use' (I've seen this in another clue).
'of sound' indicates a 'sounds like' (homophone) clue (I've seen 'sound' mean this).
'use' is a homophone of 'EWES'.
(Other definitions for ewes that I've seen before include "She-sheep" , "Females in the flock" , "wool producers" , "Sheep (females)" , "Adult sheep" .)