Sounding board
From Free net encyclopedia
The sounding board or soundboard is the largest part of a string musical instrument's body. It produces sound by resonance and transmits the reverberations of the strings to the air. Sounding boards are customarily made of wood, and most instruments have two sounding boards, an upper and a lower one. Some folk instruments have only one sounding board. An upper sounding board, the top part of the instrument's body, usually has sound holes in it. The holes can have different shapes; round in guitars, f-holes in violin family instruments, rosettes in lutes, and so on.
Sounding boards of some instruments have unique names, such as plate, or belly (the latter in a violin).
For the piano, the sounding board is the back of the instrument (if an upright) or the bottom portion of the case (if a grand piano). The harp has a soundboard below the strings.
More generally, any hard surface can act as a sounding board, for example when a tuning fork is struck and placed against such a surface to amplify the sound.