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.
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 mass, 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 passing 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, embarrasses
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 a², which I meant to be sounded,
there came the a³, 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.