Thing used by jewellers to examine ring, we hear (5)
I believe the answer is:
loupe
'thing used by jewellers to examine' is the definition.
I can't judge whether this defines the answer.
'ring we hear' is the wordplay.
'ring' becomes 'loop' (I've seen this before).
'we hear' shows a homophone (sound like).
'loop' sounds like 'LOUPE'.
Can you help me to learn more?
(Other definitions for loupe that I've seen before include "instrument in view of fine work" , "Jeweller's magnifying glass" , "Jeweller's eyeglass" , "Jeweller's eyepiece" .)