This instrument is an example of the use of reflection. It is merely a bell-shaped, or flaring body, the large end of which is directed to
the audience. The voice talking into the small end is directed forwardly, and is reflected from the sides, and its resonance also enables thep. 90 vibrations to carry farther than without the use of the solid part of the instrument.
The ear trumpet is an illustration of a sound-collecting device, the waves being brought together by reflection.
Title: Practical Mechanics for Boys
Author: J. S. Zerbe