Sound return from City house (4)
I believe the answer is:
echo
'sound return' is the definition.
(I've seen this before)
'city house' is the wordplay.
'city' becomes 'ec' (the City of London postcode).
'house' becomes 'ho' (abbreviation for house).
'ec'+'ho'='ECHO'
'from' is the link.
(Other definitions for echo that I've seen before include "Sound bouncing back" , "Response" , "Reiterate" , "Reflect in Czechoslovakia" , "Let's hear it again for the Greek nymph who loved Narcissus in vain" .)