... listener in one's middle years (3)
I believe the answer is:
ear
'listener in one's' is the definition.
'ear' can be an answer for 'listener' (body part which hears or listens). I am not sure about the 'in one's' bit.
'middle years' is the wordplay.
'middle' means to look at the middle letters.
The middle letters of 'years' are 'EAR'.
Can you help me to learn more?
(Other definitions for ear that I've seen before include "A corny bit" , "Seed-bearing part of wheat" , "See 8" , "Head of, eg, corn" , "Sense organ" .)