Sound field modelling on the basis of in-situ measurement of boundary conditions using a parametric loudspeaker

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K18920
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Architecture, Building engineering, and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Sakamoto Shinichi 東京大学, 生産技術研究所, 教授 (80282599)
• Co-Investigator(Kenkyū-buntansha): 武岡 成人 静岡理工科大学, 理工学部, 講師 (30514468)
• Research Collaborator: Sugahara Akiko
• Project Period (FY): 2017-06-30 – 2019-03-31
• Keywords: パラメトリックアレイスピーカ / 音響インピーダンス計測 / 音場モデリング / 現場測定

Outline of Final Research Achievements

In this research, accurate measurement method of sound absorption characteristics of materials by using a parametric array speaker, which can radiate test signal on target material with a limited area, was experimentally investigated. In the measurement using a parametric array speaker, negative effect of pseudo sound should be treated. Therefore, two methods, the one is application of phononic crystals as a physical acoustic filter and the other is the phase-cancellation method, were experimentally examined and their effects were confirmed. Using the method proposed in this research, normal and oblique-incidence surface acoustic impedance of porous materials was measured, and the measurement accuracy and scope of application were verified.

Free Research Field

環境音響工学

Academic Significance and Societal Importance of the Research Achievements

本研究では，新しい音響デバイスであるパラメトリックアレイスピーカの特性を利用して，材料の音響特性を精度よく計測する手法を提案した。空間の音響性能は，騒音のうるささや空間の情報伝達性能に大きく影響する。そのため，空間の音響性能を適切に保つために，空間を形作る材料の音響特性を適切に把握することが極めて重要となる。本研究で開発した計測法は，そのような材料の音響特性を，実験室であっても，実際の現場であっても正確に計測することができる。