1990 Fiscal Year Final Research Report Summary
Precision Measurements of Equal-loudness Contours
| Project/Area Number |
01550346
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
計測・制御工学
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| Research Institution | Sendai National College of Technology |
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Principal Investigator |
KUMAGAI Masazumi Sendai National College of Technology, Professor, 電子工学科, 教授 (10044653)
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| Co-Investigator(Kenkyū-buntansha) |
TAKASHIMA Hisashi Sendai National College of Technology, Assistant, 電子工, 助手 (80216887)
SUZUKI Yoiti Tohoku University, Res. lnst. Electrical Comm., Assoc. Prof., 助教授 (20143034)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Loudness / Equal-loudness contours / Minimum auduble field / Head-related transfer function |
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| Research Abstract |
A large anechoic room at Electro-technical Laboratory was used for experiments in order to get new equal-loudness contours and minimum audible field (MAF). The frequency ranges were 31.5 Hz to 12.5 kHz for 20 phon, 31.5Hz to 8 KHz for 40 phon and 63 Hz to 8 kHz for 70 phon equal-loudness contour, and31.5 Hz to 16 kHz for MAF.
The results obtained are summarized as follows ;
(1) The values of equal-loudness level below 1 kHz are higher than those of ISO 226. The maximum difference amounts to 15 dB.
(2) The MAF curve obtained is almost identical with that of ISO 226 except that out curve shows 3 to 4 dB higher in the frequency range below 160 Hz and 2 to 3 dB lower in the range above 400 Hz.
(3) A small peak is observed in the region between 1 to 2 kHz both on low level equal-loudness contours and MAF curve. This peak has not been observed in the datas of either ISO 226 or of other previous studies. THe origin of this peak is attributed to the effects of head-related transfer function.
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