Turn in bad lie about being within earshot (7)
I believe the answer is:
audible
'within earshot' is the definition.
(I've seen this before)
'turn in bad lie about' is the wordplay.
'turn' becomes 'u' (a 'U-turn' is a kind of turn).
'in' is an insertion indicator.
'about' indicates an anagram.
'bad'+'lie'='badlie'
'badlie' anagrammed gives 'adible'.
'u' going into 'adible' is 'AUDIBLE'.
'being' is the link.
(Other definitions for audible that I've seen before include "Loud enough to be heard" , "Within earshot" , "that one can catch" , "Easily caught" , "Bail due (anag.)" .)