2005 Fiscal Year Final Research Report Summary
Estimation for location of sound source of generating low-frequency noise
| Project/Area Number |
14580554
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | Shibaura Institute of Technology |
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Principal Investigator |
SHIBAYAMA Hideo Shibaura Institute of Technology, Professor, 工学部, 教授 (50052866)
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| Project Period (FY) |
2002 – 2005
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| Keywords | near field / linear microphone array / phase between the microphones / MUSIC and ESPRIT method / sound attenuation by distance / protection of environmental sound / estimation of location of noise source / direction of arrival sound wave |
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| Research Abstract |
We made an linear array microphone that is constructed by eight electret condenser microphones. Emitted sinusoidal wave signal with frequency of 80Hz from a loudspeaker, we estimated arrival direction of the acoustic waves by the MUSIC method. As estimated results, we were able to estimate the arrival direction with precision within 5 degrees. In the measurements, precision come under the influence of the signal to noise ratio in environmental sound. In addition, we have to solve a problem for multiplex reflections and diffraction waves. And, in estimating the location of the noise source by the MUSIC method, their factors strongly influence estimation precision. In the arrival direction of the acoustic waves, we used the space average method in MUSIC method and performed the measurements with the high precision as the results.
In other measurement by use of the three dimensional acoustic intensity that constructed by four electret condenser microphones, we estimated the direction of the acoustic intensity. And, from acoustic intensity measured at the three different locations, we estimated the sound noise source.
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