Hero can be heard in lounge (4)
I believe the answer is:
idle
'in lounge' is the definition.
(I've seen this before)
'hero can be heard' is the wordplay.
'hero' becomes 'idol' (I've seen this in another clue).
'can be heard' indicates a 'sounds like' (homophone) clue.
'idol' sounds like 'IDLE'.
(Other definitions for idle that I've seen before include "without basis" , "'Lazy, not doing anything (4)'" , "lndolent" , "no longer employed?" , "Run out of gear" .)