THE JOURNAL OF THE ACOUSTICAL SOCIETY OF JAPAN
Online ISSN : 2432-2040
Print ISSN : 0369-4232
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Volume 41, Issue 12
Displaying 1-13 of 13 articles from this issue
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  • Editorial comment.
    Ken'iti Kido
    Article type: Article
    1985 Volume 41 Issue 12 Pages 839-
    Published: December 01, 1985
    Released on J-STAGE: June 02, 2017
    DOIhttps://doi.org/10.20697/jasj.41.12_839
    JOURNAL FREE ACCESS
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  • Memories-The tree of acoustics.
    Yasuo Makita
    Article type: Article
    1985 Volume 41 Issue 12 Pages 840-
    Published: December 01, 1985
    Released on J-STAGE: June 02, 2017
    DOIhttps://doi.org/10.20697/jasj.41.12_840
    JOURNAL FREE ACCESS
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  • Intelligibility of frequency compressed speech for a hearing aid.
    Sotaro Sekimoto, Shuzo Saito
    Article type: Article
    1985 Volume 41 Issue 12 Pages 841-849
    Published: December 01, 1985
    Released on J-STAGE: June 02, 2017
    DOIhttps://doi.org/10.20697/jasj.41.12_841
    JOURNAL FREE ACCESS
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    A frequency compression technique for the hearing impaired was studied. In order to elucidate the validity of the frequency compressed speech for the hearing impaired, intelligibility test was made with simulated hearing loss for normal hearing subjects. Results showed that (1) the intelligibility was improved by the frequency compression for vowels, but for consonants, (2) the optimum frequency compression ratio varied depending on the individual hearing loss characteristics as well as on the formant and the fundamental frequencies of the input speech, (3) lowering of the fundamental frequency resulted in higher intelligibility in the frequency compressed speech, and (4) the improvement in intelligibility was observed in the particular vowels.
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  • A practical stochastic evaluation method for the arbitrary memory-type acoustic or vibration systems with a non-linear observation and its application to the room acoustics.
    Mitsuo Ohta, Kazumasa Nakamura, Tetsuhiro Sumimoto
    Article type: Article
    1985 Volume 41 Issue 12 Pages 850-856
    Published: December 01, 1985
    Released on J-STAGE: June 02, 2017
    DOIhttps://doi.org/10.20697/jasj.41.12_850
    JOURNAL FREE ACCESS
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    A noise or vibration system must be usually considered as a non-linear system with a finite memory, if taking a total system including sound (vibration) source, propagation mechanism and observation mechanism into consideration. In this paper, a new practical method of statistically evaluating an output probability distribution of the above system is derived consistently in one-variate form by using positively the well-known Wiener's idea on a generalized analysis of a non-linear system. That is, first, the objective system is approximately separated into two functional parts, i. e. , a zero-memory type non-linear part and a finite memory type linear part. Then, the output probability distribution can be evaluated in an approximate but generalized form, based on their typical functions. The effectiveness of the proposed method is experimentally confirmed by applying it to an actual room acoustics.
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  • Analysis of window functions for in vivo measurement of a backscattering coefficient.
    Masahiko Akita, Mitsuhiro Ueda
    Article type: Article
    1985 Volume 41 Issue 12 Pages 857-863
    Published: December 01, 1985
    Released on J-STAGE: June 02, 2017
    DOIhttps://doi.org/10.20697/jasj.41.12_857
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    It has been well-known in radar technology that the intensity of echoes scattered by a random medium can be evaluated quantitatively in term of a backscattering coefficient. In order to apply this concept to ultrasonic pulse echo techniques, the influence due to the aperture length of window must be compensated since in ultrasonics the broad band pulse is used so as to increase the resolving power of the system. Thus the measurement of backscattering coefficient must be dependent on the window length as well as the duration of ultrasonic pulse. In this paper the influence of these factors on the measurement of backscattering coefficient is analyzed under the assumptions of Gaussian function for the window, the pulse and the correlation function of tissue. And then the results are generalized to give a formula for in vivo measurement of backscattering coefficient for arbitrary window functions. Finally the availability of the formula is shown in the experiments where a sponge is used as the random medium.
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  • Directional characteristics of slow-tube waveguide radiators.
    Akio Hasegawa, Sumio Takahashi, Toshiaki Kikuchi, Teruaki Fujita
    Article type: Article
    1985 Volume 41 Issue 12 Pages 864-869
    Published: December 01, 1985
    Released on J-STAGE: June 02, 2017
    DOIhttps://doi.org/10.20697/jasj.41.12_864
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    The slow-tube waveguide, a new type of the acoustic slow waveguide radiator, is described. In this radiator, a thin-walled slow-tube waveguide is used as the basic element in an end-fire radiator. By introducing the equivalent source function within the slow-tube, the determination of the sound radiation field is conveniently carried out from the volume integral, not the surface integral. It is ascertained that Hansen-Woodyard's condition giving the optimum length of the slow-rod waveguide radiator is also valid for the slow-tube waveguide radiator. The effects of the wall thickness for long tube on the directional pattern are investigated theoretically and the superiority of the thin-walled slow-tube is confirmed. The poor directional pattern of the thick-walled slow-tube is related to the wave number ratio (k_z)/k differing substantially from (k_z)/k=1, where k_z is the wave number along the slow-tube and k the wave number of the surrounding medium. At the same time, it is clarified that the large diameter slow-tube leads to increase in directivity, especially by lowering the side lobe level.
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  • Analysis of residential noise exposure patterns and scaling of reaction of inhabitants to noise environment.
    Kazuya Takeda, Kazuhiro Kuno, Kazuo Ikegaya
    Article type: Article
    1985 Volume 41 Issue 12 Pages 870-876
    Published: December 01, 1985
    Released on J-STAGE: June 02, 2017
    DOIhttps://doi.org/10.20697/jasj.41.12_870
    JOURNAL FREE ACCESS
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    Since 1982 we have been surveyed daily noise exposure and associated informations of residences in Nagoya city. Classification of measured noise patterns of residences has been made by using cluster analysis. The five typical groups of patterns are shown to exist and they are mainly related to road traffic conditions and land use nearby residence. Then in this paper noise ratings based on L_&lteq&gt are also examined with respect to reaction of inhabitants. Scalings of reaction have been done by using Likert scale and the successive category method, on which one can quantitatively discuss the relation between L_&lteq&gt and reaction of inhabitants to noise environment. The results show that as for L_&lteq24&gt reactions of inhabitants are gentle below 55 dBA, moderate at 60 dBA, but severe over 65 dBA. The other noise ratings such as L_&ltdn&gt, L_&lteq&gtM, L_&lteq&gtD, L_&lteq&gtE, L_&lteq&gtN and L^^&lt(a)&gt__&lteq1/6&gt are also considered.
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  • The velocity of elastic waves in soil.
    Heiji Okada, Kimio Shibayama
    Article type: Article
    1985 Volume 41 Issue 12 Pages 877-880
    Published: December 01, 1985
    Released on J-STAGE: June 02, 2017
    DOIhttps://doi.org/10.20697/jasj.41.12_877
    JOURNAL FREE ACCESS
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  • Acoustic data acquisition system by use of personal computer.
    Hideaki Koga, Tomoyoshi Aoki, Naomitsu Ikeda, Ken'iti Kido
    Article type: Article
    1985 Volume 41 Issue 12 Pages 881-885
    Published: December 01, 1985
    Released on J-STAGE: June 02, 2017
    DOIhttps://doi.org/10.20697/jasj.41.12_881
    JOURNAL FREE ACCESS
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  • Recognition of vowels using the local peaks in FFT spectrum.
    Naomitsu Ikeda, Tomoyoshi Aoki, Hideaki Koga, Kyung Tae Kim, Ken' ...
    Article type: Article
    1985 Volume 41 Issue 12 Pages 886-890
    Published: December 01, 1985
    Released on J-STAGE: June 02, 2017
    DOIhttps://doi.org/10.20697/jasj.41.12_886
    JOURNAL FREE ACCESS
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  • The effect of A-weighting to frequency characteristic on vowel recognition in the running car.
    Tomoyoshi Aoki, Naomitsu Ikeda, Hideaki Koga, Kyung Tae Kim, Ken' ...
    Article type: Article
    1985 Volume 41 Issue 12 Pages 891-894
    Published: December 01, 1985
    Released on J-STAGE: June 02, 2017
    DOIhttps://doi.org/10.20697/jasj.41.12_891
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  • Correlation of speaker's physical features and speech.
    Jouji Suzuki
    Article type: Article
    1985 Volume 41 Issue 12 Pages 895-900
    Published: December 01, 1985
    Released on J-STAGE: June 02, 2017
    DOIhttps://doi.org/10.20697/jasj.41.12_895
    JOURNAL FREE ACCESS
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  • Review of text-to-speech conversion technology.
    Yoshinori Sagisaka, Hirokazu Sato
    Article type: Article
    1985 Volume 41 Issue 12 Pages 901-905
    Published: December 01, 1985
    Released on J-STAGE: June 02, 2017
    DOIhttps://doi.org/10.20697/jasj.41.12_901
    JOURNAL FREE ACCESS
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