enotes a thin broad board placed over the head of a public speaker, to enlarge or extend and strengthen his voice.

Sound-boards are found by experience to be of no use in theatres, as their distance from the speaker is too great to be impressed with sufficient force. But sound-boards over a pulpit have frequently a good effect, when the case is constructed of a proper thickness, and according to particular principles.

SOUND-Port, is a post placed in the inside of a violin, &c., as a prop between the back and belly of the instrument, and nearly under the bridge.