Examination of the ear, it's said (4)
I believe the answer is:
oral
'examination' is the definition.
(oral is a kind of examination)
'of the ear it's said' is the wordplay.
'of the ear' becomes 'aural' (I've seen this before).
'it's said' indicates a 'sounds like' (homophone) clue.
'aural' is a homophone of 'ORAL'.
(Other definitions for oral that I've seen before include "Via the mouth" , "By word of mouth, like some exams" , "Spoken - examination" , "Kind of examination" , "Spoken exam" .)