Inner ear? (3)
'inner ear?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for cob that I've seen before include "Source of bread" , "mixture of clay and straw" , "Horse, male swan and loaf of bread" , "mount" , "Hazelnut" .)
(Other definitions for corncob that I've seen before include "Woody part of maize ear" , "it's attached to grain" , "Source of a yellow vegetable" , "Central part of the maize ear" , "Smoked" .)