I will be heard in the corridor (5)
I believe the answer is:
aisle
'the corridor' is the definition.
(I've seen this before)
'i will be heard' is the wordplay.
'i will' becomes 'I'll' (abbreviation).
'be heard' shows a homophone (sound like).
'ill' sounds like 'AISLE'.
'in' is the link.
(Other definitions for aisle that I've seen before include "Corridor" , "Passage between shelves in supermarket" , "Supermarket section" , "Church walkway" , "'Passage, gangway (5)'" .)