About 1738, a merchant of Cleves, named Jorissen, who had become almost
totally deaf, sitting one day near a harpsichord, while some one was
playing--and having a tobacco-pipe in his mouth, the bowl of which
rested accidentally against the body of the instrument--was surprised to
hear all the notes most distinctly. By a little reflection and practice,
he again attained the use of this valuable sense; for he soon
learned--by means of a piece of hard wood, one end of which he placed
against his teeth, while another person placed the other end on _his_
teeth--to keep up a conversation, and to be able to understand the least
whisper. The effect thus described is the same, if the person who speaks
rests his stick against his throat or his breast; or when one rests the
stick which he holds in his teeth against some vessel into which the
other speaks.
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