Part 2 (2/2)
This closing appeared as a fine red line extending from the arytenoid cartilages at the back forward to the middle of the vocal ligaments, and leaving free only a third part of the whole glottis, immediately under the epiglottis, to the front wall of the larynx.
The foremost part of the glottis formed an oval orifice, which, with each higher tone, seemed to contract more and more, and so became smaller and rounder. The fine edges of the vocal ligaments which formed this orifice were alone vibrating, and the vibrations seemed at first looser, but, with every higher tone, the ligaments were more stretched.
The larynx remained in its natural state.
Only after I had frequently repeated this observation of the head tones in myself and in others, and had always arrived at the same results, did I venture to publish it. The most various conjectures respecting the formation of the head voice had been previously proposed by the learned, and the existence, even, of the head voice had been denied by _Bataille_. It would lead us too far away to make mention here of all these different views, which, with the exception of those of _Dr. Merkel of Leipzig_, showed themselves to be really without a sound foundation.
It was objected to the results of my observations, that such an action of the glottis ”was only possible by means of cartilages and muscles, but that such cartilages and muscles as could render an action of that kind possible were not known, nor was there any reference to them to be found in any manual of anatomy.” While I fully admitted the soundness of this objection, I was, after repeated observations, more and more convinced of the correctness of my own statements. But as I found nothing to support them in any anatomical work, either German or French, I began anew to study the anatomy of the larynx in dissected subjects.
My renewed efforts were rewarded by the discovery, within the membranes of the vocal ligaments, of those filaments or fibres of muscle which in the anatomical Appendix to this book I mention as _arytenoid-thyroid interna_, and which have also been found by other observers. They are found in all larynxes, and consist of muscular fibres, sometimes finer, sometimes thicker.[3]
At the same time I satisfied myself of the existence of a pair of cartilages--the cuneiform cartilages described in the Appendix. I found these always in the female larynx, but only now and then in the male. As these cartilages, also found within the membranes of the vocal ligaments and reaching from their junction with the arytenoid cartilages to the middle of the ligaments, are only now and then fully formed in the male larynx, but undeniably work the shutting part of the glottis, it follows plainly that only a few male voices are capable of producing the head tones.
But observation with the microscope revealed in those larynxes in which the cuneiform cartilages were wanting, parts of a cartilaginous ma.s.s, or the rudiments of a cartilage, in the place indicated.
For anatomical investigations the male larynx is commonly used, its muscles being more powerful and its cartilages firmer than in the female larynx, and this explains why anatomists in Germany have been reluctant to admit the existence of the cuneiform cartilages. It was, therefore, a great satisfaction to me to find them described under the name of cuneiform cartilages in Wilson's Human Anatomy, with the remark that they are sometimes wanting.[4]
The head register possesses a very great capacity of expansion, which, without the slightest straining, may be gradually extended, with some practice, a whole octave, and often even still farther upwards. When the transition is made from the highest tones of the falsetto register to the head register, there is experienced the same sense of relief in the organs of singing as in pa.s.sing from the chest to the falsetto register. And this is very easy to be understood, because the ligaments by this repeated partial closure of the glottis are much less stretched than in the highest tones of the preceding lower register. The difference in sound between the highest tones of the falsetto and head registers is often slight, on which account these two registers, so different in their mechanism, are easily confounded. Only in entirely healthy vocal organs can the head tones be observed. A too great secretion of mucus, or any inflammation of the mucous membrane, embarra.s.ses the formation of head and falsetto tones, while the vibrations of the fine edges of the vocal ligaments are thereby obstructed. The character of the vocal organ fully explains why in the case of sick or of worn-out voices it is always the high tones that are first lost. When I have observed, in the sick, irritation of the mucous membrane, I have often found the oval orifice which is formed in the production of the head tones entirely covered with mucus. In my own case, when by repeated effort this bubble of mucus broke, instead of the a, which I meant to be sounded, there came the a, an octave higher, which in perfect health it was never possible for me to reach. I have observed the same phenomenon sometimes in my pupils.
When one sings the scale, note by note downwards, one can sing with the action of the higher register many of the tones of the lower, without any observable straining of the organ; indeed, there is a perceptible feeling of relief; only these tones are not so full as when sung in their natural register.
ABNORMAL MOVEMENTS OF THE GLOTTIS
_Garcia_ states, in his observations, that sometimes when the rims of the vocal ligaments have come together, there remains between the arytenoid cartilages a triangular s.p.a.ce, which does not close until the tone is produced. _Czermak_ likewise describes this process in his pathological investigations, and also a similar one with the laryngoscope. While, namely, the arytenoid cartilages seem to be wholly closed, one sees just before the beginning of the tone the vocal ligaments standing apart in a square-shaped form, and only closing together with the tone. At first, before I had attained to much practice in observation, I often saw these processes in myself, and later often in others.
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.
RESULTS OF THE FOREGOING OBSERVATIONS
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? (f f?); 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 ba.s.s, 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 ba.s.s 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.
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