TABLE OF CONTENTS S. Honda and H. Hamada
Department of Information and Communication Engineering, Tokio Denki University, Tokio, Japan, Email: honda@acl.c.dendai.ac.jp
This chapter introduces a new active noise control system for optimal control of the sound field around a human's head. Geometrical arrangements of error microphones are proposed around the head in a diffused noise field. In order to evaluate the controlled sound field, a rigid sphere theoretical model is used as a human's head in the computer simulations.
In previous studies it was shown that the theoretical sphere model maintains a good approximation of a head-related transfer function (HRTF) below about 5 kHz. In this chapter the relationship between the noise reduction and the corresponding configuration of the error microphone and secondary source arrangement is evaluated. As a result, we found that the closely located secondary sources to the sphere head give significant noise reduction in a large control area. A possible arrangement of the error microphones is found to provide an optimal result according to a given control strategy, such as flatness of reduced sound pressure of the quiet zone.
In this research the aim is to achieve an effective active noise control system at both the listener's ears as well as at a relatively large area around his or her head, so that significant control can be expected even when the listener slightly moves his or her head. For this purpose, we have recently introduced a new strategy for an ANC system, in which the sound field...
