Notices positive responses on radio broadcast (4)
I believe the answer is:
eyes
'notices' is the definition.
(I've seen this in another clue)
'positive responses on radio broadcast' is the wordplay.
I cannot really see how this works, but
'positive' could be 'yes' and 'yes' is found within the answer.
A single letter 'e' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for eyes that I've seen before include "Visual organs" , "Marks on potatoes" , "Closely looks at" , "They look" , "Globular organs" .)