| Project/Area Number |
60300003
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
広領域
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
SONE Toshio Res. Inst. of Electrical Communication, Tohoku University, 電気通信研究所, 教授 (50005245)
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| Co-Investigator(Kenkyū-buntansha) |
MIURA Hajime Electro-technical Laboratory, 電子技術総合研究所, 室長
TACHIBANA Hideki Inst. of Industrial Science, University of Tokyo, 生産技術研究所, 助教授 (80013225)
KUMAGAI Masazumi Sendai National College of Technology, 助教授 (10044653)
SUZUKI Yoiti Res. Inst. of Electrical Communication, Tohoku University, 電気通信研究所, 助手 (20143034)
KONO Shunichi Res. Inst. of Electrical Communication, Tohoku University, 電気通信研究所, 助教授 (60005353)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1986: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Impact sound / impulsive noise, impact noise, noise evaluation / loudness / noisiness / energy level / ノイジネス / エネルギーレベル / ラウンドロビンテスト |
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| Research Abstract |
Impact sounds are such sound that are characterized by their high peak levels and short duration time. Thus, it is not appropriate to evaluate and to measure the loudness and the noisiness of impact sounds by conventional methods. We have studied how to evaluate the impact sounds in cooperation with ten laboratories in Japan by Grant-in-aid for Co-operative Research. As the first stage, a round robin test, in which all the participants conduct the same experiments under very similar listening condition, was carried out. In this test, we used repeated impact sounds which are generated by a mini-computer. The stimuli synthesized by a computer were recorded on magnetic tapes by using PCM. Then the tapes were distributed among researchers. This round robin test becomes a very large experiment where the number of the subjects were more than a hundred. The experimental results obtained by the test were as follows:
(1) If we express a repeated impact sound in terms of the unweighted sound exposure level, the loudness of the impact sound show rather high relation coefficient(0.97). However, to evaluate the loudness more precisely, we have to consider some time constant which is consider to represent the integral characteristic of our hearing system.
(2) As a result of the experiment for noisiness evaluation, the unweighted sound pressure level showed a very high relation coefficient(0.99). This means that this measure is quite effective to evaluate the noisiness of the repeated impact sounds.
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