Hearing a strain for ear (9)
I believe the answer is:
attention
This could be a double definition.
'hearing a strain' is the first definition.
'attention' can be an answer for 'hearing' (thesaurus). I am not sure about the 'a strain' bit.
'for ear' is the second definition.
(I've seen this in another clue)
Can you help me to learn more?
(Other definitions for attention that I've seen before include "Vigilance; care" , "Awareness - regard" , "notice" , "order to stand still" , "Special care, soldier's position" .)