抄録
The author who had studied on the apparatus of myringo-photography for a long time improved the lightsource of it by use of a ring-form strobo-flash-lamp, which was very small and gave an intensive illumination, for obtaining the sufficient photograph or cinematograph, even in the colour photography. The clinical experiments on the acoustic reflex of human tympanic muscle were carried out by the photography of tympanic membrane with use of this new apparatus, expecially to the phenomenon which was discovered by Prof. Kawata recently i. e. the retraction degree of the tympanic membrane dependent upon the location of malleus, when the object was exposed to the intense sound of various intensities, was continuously recorded. Therefore the author was able to measure exactly the above mentioned degree with aid of the enlarged figure of photograph taken by the procedure described above.
In intact tympanic membrane the increase of intensity of applied pure tone resulted in the increase of concavity with a certain characteristic. This response to the frequency of used pure tones was most sensitive in the middle tone area as 1024 cps and 2048 cps. In general the less the degree of retraction of tympanic membrane in silent state the more intene response expected.
In the experiments in which five kinds of sound were used, the retraction was augmented by increasing the phone in every sound frequency, and the responsive retraction was most sensitive to the sound of which chief component was C5 (4096 cps) and then to the higher tone area (above 4000 cps).
Besides these observations in normal persons, the experiments of the same acoustic reflex were also carried out in the cases of deafness. The retraction shifting of conductive deafness was in general very slightly in comparison with that of intact tympanic membrane, and the most sensitive response observed on the aspect of frequency in 120 phone was revealed in 4096 cps.
The retraction of tympanic membrane in the perceptive deafness, when these patients were applied the pure tones, was very slightly in contrast to that of intact one, but was generally a little larger then that of the ear of conductive deafness. This result is similar to that of normal ear of which responsive retraction is significant in the middle tone area.
The change in the deaf ear which was exposed to intensive loudness was poorer than in the normal ear, and being in the same phone intensity the response by applying the pure tones is more remarkable than that by noises. By the noise distinction the reaction was markedly recognized by the white noise and the sound of which chief component was C5 (4096cps).
The author supposes that these colour-photograpic figures of normal and pathological tympanic membrane, obtained by the new designed apparatus of myringo-photogaphy, are those which could not find out in the textbooks or references of otology up to the present.
