With the do♯ (c♯²) in the female voice and the mi♭ mi (e♭² e²) in the male voice, the arytenoid cartilages cease again to act, and as before, at the second higher series of tones of the chest register, leave the formation of the sounds to the vocal ligaments alone, which at this change appear again longer and looser, but with every higher tone tighten up to fa fa♯ (f² f♯²) in the female voice, and in the male voice to sol (g²), or as it is commonly written: g³. In the falsetto register the larynx preserves its natural position, as in quiet breathing.
When in the observation of the falsetto register I had sung upwards to its highest tones, and then sang still higher, I became aware with the fa♯ (f♯²) of a change in the motions of the organ of singing, and the tones thus produced had a different timbre from the falsetto tones. It required long and patient practice before I finally succeeded in drawing back the epiglottis so that I could see the glottis in its whole length. Not until then was I able to observe the following:
With the fa♯ (f♯²), the vocal ligaments suddenly closed firmly together to their middle, with their fine edges one over the other.
[Representation in the mirror of the organ of singing in the formation of head tones.]
a. The closing together of the vocal ligaments. b. Open part of the glottis.
The oval opening of the anterior portion of the glottis is imperfectly shown, because it is hidden from view by the epiglottis at the extreme end.
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.