Sounding-board
Pronunciation : Sound"ing-board`
Part of Speech : n.
Definition : 1. (Mus.)
Defn: A thin board which propagates the sound in a piano, in a violin, and in some other musical instruments.
2. A board or structure placed behind or over a pulpit or rostrum to give distinctness to a speaker's voice.
3. pl.
Defn: See Sound boarding, under Sound, a noise.
Source : Webster's Unabridged Dictionary, 1913