Those qualified to vote choose to speak (10)
I believe the answer is:
electorate
'those qualified to vote' is the definition.
(I've seen this before)
'choose to speak' is the wordplay.
'choose' becomes 'elect' (electing is a kind of choosing).
'to speak' becomes 'orate' (orating is a kind of speaking).
'elect'+'orate'='ELECTORATE'
(Other definitions for electorate that I've seen before include "Those qualified to vote" , "Constituency" , "Voters collectively" , "choosing body" , "Everyone choosing" .)