Chapter 7

SOUND--THE LARYNGOSCOPE--THE LARYNX RECONSIDERED.

Some study of physics desirable--Sound and vibrations--The sounding body--Experiments to illustrate the principles of sound--Qualities of sound--Animals and perception of sound--The range of hearing in man--The larynx as a musical instrument--Experiments of Johannes Müller--Discovery of the laryngoscope by Garcia--Description of the instrument--Method of using the laryngoscope--The difficulties--Auto-laryngoscopy--The importance of both laryngoscopy and auto-laryngoscopy--Change in size of the larynx due to use--Delicate changes in the laryngeal mechanism--Changes in the larynx during adolescence--Warnings--The "breaking" of the voice--Analogies with fatigue, etc.--When should singing be begun?--Singing with others--Choral singing 97