A Spatial Audio System Using Multiple Microphones on a Rigid Sphere

• Published in: ETRI journal Vol. 27; no. 2; pp. 153 - 165
• Main Authors: Lee, Tae-Jin, Jang, Dae-Young, Kang, Kyeong-Ok, Kim, Jin-Woong, Jeong, Dae-Gwon, Hamada, Hareo
• Format: Journal Article
• Language: Korean
• Published: 한국전자통신연구원 01.04.2005; ETRI
• Subjects: 전자/정보통신공학; sphere microphone; dummy head microphone; 3D audio; HRTF
• ISSN: 1225-6463; 2233-7326

The main purpose of a spatial audio system is to give a listener the same impression as if he/she were present in a recorded environment. A dummy head microphone is generally used for such purposes. Because of its human-like shape, we can obtain good spatial sound images. However, its shape is a restriction on its public use and it is difficult to convert a 2-channel recording into multi-channel signals for an efficient rendering over a multi-speaker arrangement. In order to solve the problems mentioned above, a spatial audio system is proposed that uses multiple microphones on a rigid sphere. The system has five microphones placed on special points of the rigid sphere, and it generates audio signals for headphone, stereo, stereo dipole, 4-channel, and 5-channel reproduction environments. Subjective localization experiments show that front/back confusion, which is a common limitation of spatial audio systems using the dummy head microphone, can be reduced dramatically in 4-channel and 5-channel reproduction environments and can be reduced slightly in a headphone reproduction.