One can read it by ear (5)
I believe the answer is:
morse
'one can' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'it by ear' is the wordplay.
I cannot really see how this works, but
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is found within the answer.
The remaining letters 'mors' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
'read' is the link.
Can you help me to learn more?
(Other definitions for morse that I've seen before include "Kind of code" , "TV inspector" , "Fictional inspector; code" , "Samuel ---, telegraph inventor" , "Oxford detective" .)