lithophone

noun2

1. •
   Any musical instrument in which sound is produced by percussion of a stone.

   • Lithophones are the oldest of the bar idiophones. We have already mentioned the ten note neolithic lithophone from Vietnam, but such instruments have died out. — 1970
2. •
   (old-fashioned) A device by which the presence of bladder stones can be audibly detected.

   • It is needless to dwell on the utility of the lithophone for finding vesical calculi and small fragments after lithotrity. The instrument in figured in Le Progrés Medica, 3 April, 1880. — 1880