Soundingboard

[Dorothey Allen]

A board or screen placed over or behind a pulpit or stage to reflect a speakers voice forward.

[Ernesto]

1a : a structure behind or over a pulpit, rostrum, or platform to give distinctness and sonority to sound. b : a device or agency that helps propagate opinions or utterances. c : a person or group on whom one tries out an idea or opinion as a means of evaluating it.