Sound clear and brilliant inside skull — is this needed? (7,3)
I believe the answer is:
hearing aid
'this needed?' is the definition.
The definition suggests a singular noun which matches the answer.
'sound clear and brilliant inside skull' is the wordplay.
I cannot quite understand how this works, but
'sound' could be 'ring' (ring is a kind of sound) and 'ring' is present in the answer.
'brilliant' could be 'ai' (resembles 'A1', old-fashioned term for excellent) and 'ai' is found in the answer.
'skull' could be 'head' (I've seen this in another clue) and 'head' is found in the remaining letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'is' is the link.
Can you help me to learn more?
(Other definitions for hearing aid that I've seen before include "asset in court?" , "Help for the partially deaf" , "Earpiece" , "Amplifier for ear" , "Ear trumpet" .)