Insect has been quiet (4)
I believe the answer is:
wasp
'insect' is the definition.
(I know this)
'been quiet' is the wordplay.
'been' becomes 'was' (being is a kind of being).
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'was'+'p'='WASP'
'has' acts as a link.
(Other definitions for wasp that I've seen before include "White Anglo-Saxon Protestant" , "Striped insect" , "Insect with a sting in its tail" , "colonist" , "Swap for a stinging insect" .)