巻号一覧
10 巻 (1954)
- 4 号 p. 217-
- 3 号 p. 127-
- 2 号 p. 65-
- 1 号 p. 1-
10 巻, 3 号
選択された号の論文の10件中1～10を表示しています
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松沢 喜一郎原稿種別: 本文
1954 年 10 巻 3 号 p. 127-130
発行日: 1954/09/30
公開日: 2017/06/02
ジャーナル フリーThe effect of water absorbed in barium-titanate ceramic transducers, which emitted 2 Mc ultrasonic wave in water, was studied. Usually the water penetration into ceramics was very slow. Experimental results showed that there's almost no effect of the water on the ultrasonic emitting ability of ceramics, even in samples which absorbed water in consideralbe amount. Here, emitting ability meaned the minimum voltage applited on ceramics to maintain a constant ultrasonic radiation, the pressure of which was measured by a balance.抄録全体を表示PDF形式でダウンロード (375K) -
菊池 喜充, 清水 洋, 阿部 公一原稿種別: 本文
1954 年 10 巻 3 号 p. 130-137
発行日: 1954/09/30
公開日: 2017/06/02
ジャーナル フリーSaneyoshi's radiation pressure meter of open-tube type is convenient for use in making measurements of ultrasonic intensity in liquid. However, its sensitivity is small and moreover is possessed with the drawback of presenting difficulties in the adjustment of the meniscus level of the liquid in the tube. We have improved it by narrowing down the inner diameter of the N-shaped tube around the reading scale and setting the tube at an angle. The sensitivity was thereby increased by seven times. Moreover, by connecting with a rubber tube the N-shapped tube and the probe-tube in the sound field, we have much simplified the adjustment of the meniscus level, this being done by merely turning a screw pressing on the rubber tube. We have tested this meter in actual use by measuring ultrasonic waves of 0. 2-3 watts/cm^2 at 28 kc and proved its practical value.抄録全体を表示PDF形式でダウンロード (661K) -
二村 忠元, 城戸 健一原稿種別: 本文
1954 年 10 巻 3 号 p. 137-144
発行日: 1954/09/30
公開日: 2017/06/02
ジャーナル フリーIn our researches on the cone type dynamic loud-speaker, we studied the dynamic properties of the paper used as material for the conical radiator, and methods of producing better paper for this purpose were explored. To attain this end, we have devised a schematic paper model based on the following assumptions founded on experiment: i) The fibres are assumed to be straight between two adjoining junctions with other fibres. ii) When the paper is deformed, no slip occurs between two fibres, while at the junctions of the fibres the angles between two connected fibres remain constant. iii) Each fibre is rigidly fixed at the junctions, and the direction of the fibre remains stationary as referred to coordinates fixed in space, when a uniform stress is imposed on the paper. Calculations on the above schematic model resulted in the following conclusious: 1. The young's modulus changes proportionally to the square of the volume density when the paper (pulp) is pressed while wet and then dried. 2. The Young's modulus, the propagation velocity of longitudinal waves through the paper and the density of the paper are each proportional to the respective constants of the fibres. 3. The effect of the structure of the paper on the Young's modulus, the density, the porpagation velocity and the Poisson's ratio of the paper were made clear. 4. When the directions of the fibres are not evenly distributed, the Young's modulus is maximum in the direction of the maximum concentration of the fibres. 5. The Poisson's ratio depends upon the structure of the paper, and may exceed 0. 5 in cases where the directional distribution of the fibres is sharply biased.抄録全体を表示PDF形式でダウンロード (602K) -
大野 壽彦, 河合 平司原稿種別: 本文
1954 年 10 巻 3 号 p. 144-148
発行日: 1954/09/30
公開日: 2017/06/02
ジャーナル フリーThe change of the effective volume of the auditory canal caused by a strong sound was studied with the aid of a small acoustic pipe of T form. The pipe was held against one ear while an earphone was set on the other. First, the normal effective volume of the auditory canal was measured when no sound was introduced. The measurement was repeated with the strong sound issuing from the earphone. A change in the effective volume was observed when the sound intensity reached about 80 db. With stronger sounds the change was in proportion to the increase of the intensity of this auxiliary sound. In the lower frequencies below ca. 600 cps however the effective volume actually decreased, for instance by about 0. 1 cc at 400cps when the sound intensity was 120 db, as contrasted to an increase of about 0. 1 cc at 1000 cps with the same intensity. This is in spite of the fact that the resonance frequency of the middle ear mechanism remains unchanged at about 800 to 1200 cps. These phenomena may be explained by the increase of resistance in the middle ear mechanism. The influence of the change of the effective volume on the sense of hearing was measured. A bone-conduction and an air-conduction receiver were attached to one ear, and to the other ear an air-conduction earphone for emitting strong sound. First, the bone and air-conducted tones were adjusted to the same level as perceived by the one ear. Next, the strong sound was introduced to the other ear and again the bone and air-conducted tones were balanced to the same hearing level by means of attenuators. Perception of both the air and boneconducted tones was dulled with the accompaniment of the auxiliary sound when it exceeded about 80 db, the extent of this attenuation being more pronounced in the case of the bone as compared to the air-conducted tone. This relative difference in perception between bone and air couducted sound increased with the intensity of the auxiliary sound, being about 4 db at 100 db and 7 to 10 db at 120 db. This effect changed little with the frequency of the strong sound. The decrease of the sensitivity of both air and bone-conducted sound is considered to be due to the action of the inner ear.抄録全体を表示PDF形式でダウンロード (422K) -
永井 健三, 佐藤 利三郎, 岩崎 俊一原稿種別: 本文
1954 年 10 巻 3 号 p. 149-154
発行日: 1954/09/30
公開日: 2017/06/02
ジャーナル フリーThe advent of the multi-channel sound recording system has stimulated developements in the stereo-phonic reproduction of magnetically recorded signals, and has inspired much active discussion by research workers on the boundary conditions of stereo-phonic reporduction. But these discussions hitherto have chiefly dealt with the sound space of travelling wave fronts radiated from scattered sound sources, and have neglected the aspects of transformation between the physical properties and the auditory sensation. Based on these observations, we experimented with the transitional phenomena existing between the factors of time, phase and amplitude of the sound waves and the hearing sensation, and we have clarified their effect on the directional localization of sound sources with the aid of binaural and the stereo-phonic methods. It was recognized that the factors of the difference in the amplitude of the signals entering the two ears is the most important in directional localization of steady-state sound signals, and an amplitude difference of 0. 2db clearly produces a sensation of change in the direction of the source. Moreover, the transient response of our hearing organ is so sensitive that the time difference in the received signals also constitutes another very important factor.抄録全体を表示PDF形式でダウンロード (614K) -
大泉 充郎, 久保 栄一原稿種別: 本文
1954 年 10 巻 3 号 p. 155-158
発行日: 1954/09/30
公開日: 2017/06/02
ジャーナル フリーA multivibrator and a noise generator combined with 10 band pass filters were used as sound source. Tones corresponding to consonants, vowels and transients were previously recorded on strips of magnetic tape. They were then cut into suitable lengths and pieced together in proper order to reproduce given sounds occurring in speech. The sounds roughly corresponding to A, I, U, E, O, K, S, Sh, T, N, H, M, Y, and W have so far been successfully synthesized by the above method.抄録全体を表示PDF形式でダウンロード (360K) -
栗原 嘉名芽原稿種別: 本文
1954 年 10 巻 3 号 p. 159-160
発行日: 1954/09/30
公開日: 2017/06/02
ジャーナル フリーPDF形式でダウンロード (329K) -
実吉 純一原稿種別: 本文
1954 年 10 巻 3 号 p. 161-167
発行日: 1954/09/30
公開日: 2017/06/02
ジャーナル フリーPDF形式でダウンロード (857K) -
早坂 壽雄原稿種別: 本文
1954 年 10 巻 3 号 p. 168-176
発行日: 1954/09/30
公開日: 2017/06/02
ジャーナル フリーPDF形式でダウンロード (1101K) -
小野 俊原稿種別: 本文
1954 年 10 巻 3 号 p. 177-182
発行日: 1954/09/30
公開日: 2017/06/02
ジャーナル フリーPDF形式でダウンロード (794K)
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