My old suspicion is voiced — pay attention! (4,3)
I believe the answer is:
mind out
'my old suspicion is voiced pay' is the definition.
I can't judge whether this definition defines the answer.
'attention' is the wordplay.
I cannot quite understand how this works, but
'attention' could be 'mind' (mind is a kind of attention) and 'mind' is present in the answer.
The remaining letters 'out' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
(Other definitions for mind out that I've seen before include "Cave" , "Beware!" .)