opeidoscope

noun1

1. •
   An instrument, consisting of a tube with one end open and the other end covered with a thin flexible membrane with a mirror attached to its centre, used for exhibiting upon a screen, by means of rays reflected from the mirror, the vibratory motions caused by sounds that enter the tube.

   • I can't help thinking that, had he lived to see the electronic cricket sensor, the inventor of the opeidoscope probably would have approved. — 2009