Sounds a liar, but worth a hearing (4)
I believe the answer is:
lyre
'worth a hearing' is the definition.
I can't tell whether this defines the answer.
'sounds a liar' is the wordplay.
'sounds' shows a homophone (sound like).
'liar' sounds like 'LYRE'.
'but' is the link.
Can you help me to learn more?
(Other definitions for lyre that I've seen before include "Ancient Greek stringed instrument" , "Type of harp" , "Early harp" , "Harp used by ancient Greeks" , "Old instrument, like a harp" .)