0 a person or group of people that you use to test something such as a new idea or suggestion to see if they will accept it or if they think it will work
1 someone you use to test a new idea or suggestion to see if it is liked:
It is a sounding board, in some ways, as to the opinions of the various nation states.
I mean that in the sense not of being oppositionist but of being a sounding board and providing a different view from time to time.
It is the sounding board of the nation.
It would be a team that could work together and not a collection of individuals and still less a sounding board for particular interests.
It is a great sounding board for public opinion.
It cannot be the sounding board for one speaker, because it is not.
It acts as a confidential sounding board for proposed policy initiatives and as an avenue for the discussion of representatives' concerns and proposals for change.
After all, this place is a great sounding board.
