When those who had become accustomed to the introduction of the instrument sang, at my request, a, as pronounced in the English word man, in a deep tone, the epiglottis rose, the tongue formed a cavity from within forwards, and thus rendered it easy to see into the larynx. So soon as the a, as in father, was sung, the cover quickly fell, the tongue rose, and prevented all observation of the organ of singing. The other vowels are still less favorable to observation, because they do not admit of any such wide opening of the mouth. Strong tones also are unfavorable to observation, as Garcia also remarked; and this is very natural, because strong and sonorous tones require greater exertions of the singing organ, and, above all things, the right position of those parts of the larynx and mouth which serve as a resonance apparatus in the formation of sound. In order to be able to see perfectly the whole glottis, all this resonance apparatus must be drawn back as far as possible, and the rim of the larynx must be tolerably flat. Thus only faint and weak sounds are favorable to observation.
THE CHEST REGISTER
When the vowel a, as in man, was sung, I could, after long-continued practice, plainly see how the arytenoid cartilages quickly rose with their summits in their mucous membranous case and approached to mutual contact. In like manner, the chordæ vocales, or inferior vocal chords, approached each other so closely that scarcely any space between them was observable. The superior or false vocal ligaments formed the ellipse described by Garcia in the upper part of the glottis.
Representation in the mirror of the vocal organ in giving out sound.
a. Superior or false vocal ligaments, or chords.
b. Epiglottis.
c. Inferior or true vocal ligaments.
d. Arytenoid cartilages.
e. Capitula Santorini.