Says one's piece in a high voice? (6,2)

'says' is the definition.
The definition and answer can be both to do with communicating as well as being verbs in their -s form.
Maybe there's an association between them I don't understand?

'one's piece in a high voice?' is the wordplay.
I cannot really see how this works, but
'piece' could be 'p' (abbreviation for Pawn) and 'p' is found within the answer.
'a' is within the answer.
'high' could be 'up' (associated in meaning) and 'up' is found in the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?