That these accidental forms of the glottis bear no relation to the generation of sounds, as _Funke_ truly says, is made evident by an irregularity in the combined action of the muscles of the larynx, by which the coming together of the arytenoid cartilages takes place later than that of the ligaments, or that of the ligaments later than that of the arytenoid cartilages.
As recently great importance has often been ascribed to these abnormal movements of the glottis in the generation of sound, I have felt bound to mention them.
In consequence of the observations above described, the following facts may be established:
I. We have found five different actions of the vocal organ:
1. _The first series of tones of the chest register_, in which the whole glottis is moved by large, loose vibrations, and the arytenoid cartilages with the vocal ligaments are in action.
2. _The second series of the chest register_, when the vocal ligaments alone act, and are likewise moved by large, loose vibrations.
3. _The first series of the falsetto register_, where again the whole glottis, consisting of the arytenoid cartilages and vocal ligaments, is in action, the very fine interior edges of the ligaments, however, being alone in vibrating motion.
4. _The second series of the falsetto register_, the tones of which are generated by the vibrations of the edges alone of the vocal ligaments.
5. _The head register_, in the same manner and by the same vibrations, and with a partial closing of the vocal ligaments.
II. We have learned the transitions of the registers, i.e., those tones where a different action of the vocal organ takes place; and observation has further taught us that these _natural limits of the registers cannot be exceeded without a straining that may be both seen and felt_; that is, that we may not preserve the action of a lower series for the tones of a higher. On the other hand, the vocal organs show _no straining_ when the action of a higher series of tones is kept for a lower, only the fulness of the tones is thereby diminished.
III. We have further seen that _only the transition from the chest register to the falsetto is in all voices at the same tones_, the fa fa♯ (f¹ f♯¹); but, both in men's and women's voices, the other _transitions of the registers are different_. As the male larynx is about a third larger than the female, it is plain that the registers in the male voice have a greater expansion. The transitions, however, in the tenor, as in the bass, are at the same tones, and only sometimes a half tone higher or lower in one voice than in another. The organs of the man are stronger and harder than those of the woman, and they are not often capable of producing tones with the vibrations of the edges of the vocal ligaments (falsetto tones), but the lower series of tones of the chest register has, in such voices, a much greater extension downwards. _The difference between the bass and tenor voices lies in the greater or less ease with which the tones of the higher or lower registers are sung, and in the greater fulness and beauty, always connected therewith, of the higher or lower register, that is, in the timbre of the voice_; not, as is commonly thought, in the difference of the transitions of the registers.