Title:
METHOD AND DEVICE FOR MEASURING SOUND ABSORPTION RATE
Document Type and Number:
Japanese Patent JPH03276031
Kind Code:
A
Abstract:
PURPOSE:To increase the measurement accuracy of the sound absorption rate by finding the spatial gathering mean of reverberation when a sound source is interrupted, finding the extent of curvature of the reverberation waveform and the reverberation time of the linear attenuation in a complete diffused sound field to the attenuation rate, and then finding the sound absorption rate of a material. CONSTITUTION:When the impulse response by a single-sound generating device 1 is generated from a speaker 3, a microphone 4-1 absorbs the sum of an impulse and a noise. This signal is converted by an A/D converting circuit 7 and squared by a squaring circuit 8, a subtracting circuit 23 subtracts the effective value of the noise, and an accumulator 11 perform sequential accumulation. Sounds are collected by microphones 4-2 - 4-n in order and accumulated values are added in a RAM 14. The arithmetic result indicates the spatial gathering mean value, which is compressed logarithmically in a ROM 17 to find a reverberation curve. The measurement is performed when a reverberation room 2 is empty and when chairs (b) are put in, and the reverberation time and the sound absorption rate of the sound absorber are found.
Inventors:
KAWAKAMI FUKUJI
SAKAI TAKESHI
SAKAI TAKESHI
Application Number:
JP7839490A
Publication Date:
December 06, 1991
Filing Date:
March 27, 1990
Export Citation:
Assignee:
YAMAHA CORP
International Classes:
G01H7/00; (IPC1-7): G01H7/00
Attorney, Agent or Firm:
Masatake Shiga (2 outside)
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