Sound position, in a sense (5)
I believe the answer is:
sight
'a sense' is the definition.
(sight is a kind of sense)
'sound position' is the wordplay.
'sound' shows a homophone (sound like).
'position' becomes 'site' (site is a kind of position).
'site' sounds like 'SIGHT'.
'in' acts as a link.
(Other definitions for sight that I've seen before include "Vista" , "Observe" , "Power of vision" , "a great deal" , "Device used in aiming" .)