The loudspeaker array with a high directivity and an arbitrary beam rotation

2015 Fiscal Year Final Research Report

• Project/Area Number: 25330187
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Perceptual information processing
• Research Institution: The University of Electro-Communications
• Principal Investigator: Haneda Yoichi 電気通信大学, 情報理工学(系)研究科, 教授 (80647496)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: スピーカアレー / 球面調和関数 / ビームフォーマ / 最小分散法 / 指向性 / 正多面体

Outline of Final Research Achievements

We investigated the loudspeaker array which has a high directivity and an arbitrary beam rotation. The filter of a spherical loudspeaker array is designed based on the minimum variance method in the spherical harmonics domain. The beam pattern generated by the filter achieves a high directivity in a certain direction. Further, the beam direction can be rotated while maintaining the shape of the beam pattern. We implemented a prototype system that allows the listener to steer the beam direction using a gyro sensor in real time. The listening test result suggested that the location of the sound image varies based on the sound reflected from the wall. We evaluated the sound localization mechanism while rotating the beam direction based on the observed signal measured with a dummy head. The result showed that the sound of the beam reflected from a wall influences horizontal plane localization and sound image distance.

Free Research Field

音響信号処理