Heard quiet section (5)
I believe the answer is:
piece
'section' is the definition.
(I've seen this in another clue)
'heard quiet' is the wordplay.
'heard' indicates a 'sounds like' (homophone) clue.
'quiet' becomes 'peace' (I've seen this before).
'peace' sounds like 'PIECE'.
(Other definitions for piece that I've seen before include "Slice" , "wedge a > bit" , "E.g. bishop" , "one of eight once ready for the Spanish?" , "Portion, bit" .)