Doctor hopes men become sound (7)
I believe the answer is:
phoneme
'sound' is the definition.
(speech sound)
'doctor hopes men' is the wordplay.
I cannot quite understand how this works, but
'doctor' could be 'me' and 'me' is found within the answer.
The remaining letters 'phone' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'become' is the link.
Can you help me to learn more?
(Other definitions for phoneme that I've seen before include "distinctive sound" , "Unit of spoken sound" , "Small bit of speech" , "minimal piece of speech" .)