Hear again about something improved by conversion (5)
I believe the answer is:
retry
'hear again' is the definition.
('try' can be a synonym for 'hear' so perhaps 'retry' is OK for 'hear again')
'about something improved by conversion' is the wordplay.
I cannot quite see how this works, but
'about' could be 're' (regarding) and 're' is found in the answer.
The remaining letters 'try' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for retry that I've seen before include "Have another go" , "Hear (a case) again" , "Advice following failure, initially" , "take second opinion on case" , "Put on trial again" .)