| Project/Area Number |
03452228
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
建築環境・環境工学
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
FUJIMOTO Kazutoshi Dr. Eng., A.Prof., Faculty of Eng., Kyushu University, 工学部, 助教授 (90112309)
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| Co-Investigator(Kenkyū-buntansha) |
FURUYA Hiroshi Mr. Eng., Lec., Faculty of Eng., Kyushu University, 工学部, 講師 (00238700)
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| Project Period (FY) |
1991 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥6,900,000 (Direct Cost: ¥6,900,000)
Fiscal Year 1993: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1992: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1991: ¥4,500,000 (Direct Cost: ¥4,500,000)
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| Keywords | Room Acoustics / Concert Hall / Balcony / Direct Sound / Early Reflections from Upside / Psycho-Acoustical Experiment / Auditory Impression of Envelopment / 模型実験 / 音響設計 / コンサ-トホ-ル / バルコニ- |
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| Research Abstract |
A balcony overhang is frequently set up in auditoria. The sectional shape of the under-balcony space is one of the most important factors for good acoustics in auditoria. The acoustical properties under the overhang, however, have not been clarified yet and there is so far no generally accepted criteria for acoustical of the balcony configuration. The object of this study is to make clear the relation between the shape of the balcony and the acoustical properties.
As the second step, the subjective effects of the delay time(DELTAt) and the level(L) of reflections from upside is examined by psycho-acoustical experiments, because the structure of early reflections from upside, which is affected by the presence of a balcony, is regarded as one of the causes of acoustical defect under the balcony in auditorium. Simulated music sounds with a single or two reflections are uesd as stimuli. The results show that auditory size of sound image becomes smaller as DELTAt and L are smaller. Next, simulated music sound with early reflections both from horizontal directions and from upside are used as stimuli. The results show that envelopment becomes stroger as vertical component of reflected energy increases when lateral energy fraction is constant. These facts suggest that lack of early reflections from ceiling above main orchestra is a factor for disturbing good acoustics under the balcony.
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