INTRA-TYMPANIC PRESSURE DURING PHONATIOt^. 
[Reprinted from tiie Transactions of the American Otoeogical Society.] 
CLARENCE J. BLAKE, M. D., BOSTON. 
The two principal factors in the production of articulate 
sounds being the expulsion of air from the lungs, and the 
variations in position of different parts of the larynx, naso- 
pharyngeal and buccal cavities, changes in the degree of 
pressure in these cavities necessarily result and play an im- 
portant part in the production of articulate sounds. 
This subject has been considered by Dr. Henry J. Bigelow, 
in his experiments on articulation in cases of cleft palate, as 
the result of which he has given rules for practice in phona- 
tion which should enable the patient, by varying the pressure 
in the buccal cavity, to accommodate the position of the tongue 
and lips to the abnormal condition of the roof of the mouth, 
and thereby increase the clearness of articulation.* It is evi- 
dent that under normal conditions the changes in the contour 
of the buccal cavity during phonation result in correspond- 
ing variations of pressure in the mouth and in the naso- 
pharyngeal space ; and the case in which the following tests 
were made proves conclusively that this jiressure is sufficient 
to be communicated through the Eustachian tube to the 
middle ear: — 
The patient, a man thirty years of age, had a purulent 
inflammation of the left middle ear, the result of an attack 
of scarlet fever in his fourth year. Up to the time when first 
examined, the purulent discharge had continued, in varying 
quantity, for twenty-four years. Examination of the ear 
* Boylston Prize Dissertation, 1844. 2 
showed almost entire destruction of the membrana tympani, 
and a granular condition of the mucous membrane of the tym- 
panic cavity, with well-marked polypoid granulations about 
the head of the malleus and incus, and hanging down into 
the cavity. As the result of careful cleansing, the use of 
astringents, and the application of caustics, the granula- 
tions disappeared, the discharge diminished, and a cicatricial 
growth, starting from the periphery of the membrane and 
from about the malleus, formed a septum between the.lower 
and anterior portion of the tympanic cavity and the outer 
ear. 
This septum, as is the case in cicatrices of the membrana 
tympani, was thinner than the membrana tympani itself, and 
its larger segment, extending across the anterior portion of 
the tympanic cavity opposite the opening of the Eustachian 
tube, was exceedingly lax and could be easily made to bulge 
outward by forcing air up through the Eustachian tube. 
About the 1st of June, 1875, the patient appeared, speaking 
very much as if he were suffering from a " cold in the head ” ; 
that is, the m, n, and ng sounds were pronounced b, d, and g ; 
"manner,” for instance, was pronounced " badder,” with a 
very slight nasal sound, and " managing,” " badagig.” There 
were no other symptoms of a cold, however, and he explained 
the peculiar pronunciation as a voluntary effort to suppress 
the nasal sounds, m, n, and ng, substituting the correspond- 
ing media, because the former were accompanied by a very 
disagreeable crackling and bursting sound in the left ear. 
This sound was less on pronouncing m, greater on pronoun- 
cing n, and most disagreeable of all on pronouncing ng. An 
examination of the left ear while the patient sounded the nasal 
checks, showed that, with each sound, the lax cicatrix extend- 
ing across the tympanic orifice of the Eustachian tube exe- 
cuted a corresponding movement. With m, the membrane 
made a slight excursion outward and fell back into its former 
position ; with n, the excursion was still greater ; and with ng, 
a double excursion was observed, the membrane only partially 
resuming its original position between the two movements. 3 
The movements of the membrane as to duration and extent ot 
the excursion being represented by the following curves, which 
correspond very nearly to the logogranhic tracings of m, n, 
and ng,—thus, m, n, ng, 
By pressing a probe against the membrane its excursions 
were partially controlled, and the unpleasant sensations in 
the ear correspondingly diminished. A piece . of cotton 
tightly packed at the bottom of the meatus was still more 
effectual, but this improvement lasted only a few hours, as 
the cotton was easily displaced. As a final remedy, a portion 
of the membrane was excised, leaving a circular opening, 
through which air forced through the Eustachian tube passed 
freely. The movements of the membrane immediately ceased, 
the nasal sounds Avere pronounced clearly and with the usual 
resonance; and the opening remaining, up to the last exami- 
nation, there had been no return of the unpleasant symptoms 
in the ear, and the voice was as clear as usual. 
Immediately after the operation and for the purpose 
of experiment, a manometer made of barometer tube bent 
into U form, and having a bore 1 millimetre in diameter, 
filled with water, was inserted in the outer ear, closing the 
opening. The pronunciation of the nasal checks pro- 
duced a movement in the column of fluid exactly corre- 
sponding to the movement of the membrane before per- 
foration : for the m sound, there was a rise and fall of the 
column } millimetre ; for the n sound, a rise and fall of 
nearly 1 mm. ; and for the ng sound, a double rise and fall for 
nearly the same degree. The tube was then placed in one 
nostril and the other nostril closed; for the m sound, the 
column rose 1G millimetres, for the n sound, 20 mm., and for 
the final impulse of the ng sound, with the same double 
movement as before, 26 millimetres. 
The same test, in a patient having no perforation of the 
membrana tympani, showed the same proportion of movement 
for the several nasal checks. The movements of the membrane 
in the case described, and of the manometric column, when the 4 
tube was placed in the ear, show a certain pressure in the 
naso-pharyngeal space, corresponding to each of the three 
nasal sounds, and an examination into the position of the 
lips, tongue, and palate, in the production of m, n, and ng, 
shows a corresponding diminution of the capacity of the 
buccal cavity. Thus, in producing m, the [position is as 
follows : — 
The lips closed and tongue depressed. The 
capacity of the buccal cavity being consider- 
able, and the pressure in the naso-pharyngeal 
cavity correspondingly small. This is shown 
by the lesser movement of the membrane in the 
ear, and of the fluid column in the manometer. 
In producing n, the lips are slightly apart, and the tip 
of the tongue pressed against the hard palate, 
just behind the teeth. The capacity of the 
buccal cavity is diminished, and the pressure 
in the naso-pharyngeal space proportionately 
greater, as shown by the greater movement 
of the membrane in the ear and the mano- 
metric column. 
In producing ng, the top and back of the tongue are 
pressed upward, still further diminishing the resonant capa- 
city of the buccal cavity, and allowing the full 
force employed in the production of the sound 
to expend itself in the nares and naso-pharyn- 
geal cavity, back of the elevated tongue. 
Helmholz says, " m and n resemble the vowels 
in their formation, because they cause no noise 
in the buccal tube. The buccal tube is shut and the voice 
escapes through the nose. The mouth only forms a resonating 
cavity modifying the sound.” As we have seen, in m the 
buccal cavity is closed at its farthest anterior limit by the lips, 
and the cavity has full resonance. In sounding n, it is closed 
by the tip of the tongue a little farther backward and its reso- 
nant capacity diminished, while in the full nasal sound, ng, 
it is closed at its posterior limit by the elevation of the top 5 
and back of the tongue, and its resonant capacity is very little. 
Merkel* tested the pressure in the nasal cavity by holding 
a bit of down or a light feather in front of the nostrils. On 
sounding a pure vowel the feather remained motionless, the 
air passing out through the buccal cavity; but on sounding a 
nasal tone, the feather was set in motion. 
Max Mullerf says, b, d, and g, may be modified to m, n, 
and ng ; for these nasals a full contact takes place (that is, of 
lips or tongue and roof of mouth), but the breath is stopped, 
— not abruptly (as in p, t), but in the same manner as with 
the media (as in b, d, g), —at the same time the breathing 
is emitted through the nose. In the present case the un- 
pleasant sensation in the ear caused the patient to seek relief 
by substituting the media, b, d, and g, for the nasal tones, 
thus allowing the air to pass out through the mouth and 
diminishing the pressure in the pharynx and Eustachian tube 
and ear. In the formation of the nasal tones, in this case, it 
has been interesting to note an increase of pressure in these 
parts proportionate to the degree of closure of the buccal 
cavity; and the case suggests a series of tests of the distri- 
bution of pressure in the formation of consonant sounds, 
which would certainly be of interest and possibly of value. 
* Der Kehlkopf, p. 2G8. 
f Science of Language, p. 158.