Hang about for hearing, having influence (6)
I believe the answer is:
weight
'influence' is the definition.
(I know that weight is a type of bias)
'hang about for hearing' is the wordplay.
'hang about' becomes 'wait' (I've seen this before).
'for hearing' shows a homophone (sound like).
'wait' is a homophone of 'WEIGHT'.
'having' acts as a link.
(Other definitions for weight that I've seen before include "Relative heaviness" , "Importance, heaviness" , "Import" , "Attach importance to" , "Pressure" .)