Computational systems for sound fields, as tools in design and diagnosis

Abstract

Computational systems for design and diagnosis of sound field were developed. The concept of these systems are based on the model of human auditory-brain system [Y. Ando, Architectural Acoustics -Blending Sound Sources, Sound Fields, and Listeners (AIP/Springer-Verlag, New York, 1998)], including the autocorrelation mechanisms, interaural cross-correlation mechanism, and the specialization of the human cerebral hemispheres. Thesis consists of following four parts: (1) Computer simulation system for calculating the four orthogonal factors (LL, t1, Tsub and IACC) at each seat using architectural drawings were developed. The accuracy of this system were examined by comparing the calculated factors with the measured ones at Kirishima International Concert Hall. (2) The diagnostic system to measure the four orthogonal factors and additional factors (,IACCWIACC and A-value) was developed. This system can be used for the measurement in the scale model. The effect of the reflectors' array above stage which can not calculate at the design stage was evaluated at the scale model measurement of Tsuyama music cultural hall. (3) As an application of the subjective preference theory, seat selection system to maximize the preference of each individual was developed. This system, which is installed in Kirishima International Concert Hall, can find the seat where the preference is maximized by the paired comparison test with respect to the four orthogonal factors. (4) Noise measurement system to measure and identify the environment noise using the factors extracted from the autocorrelation function ( (0),e, 1 and 1) and the factors extracted from the interaural crosscorrelation function (IACC, ,IACC and WIACC) was developed. As an example, noises from different car engines were characterized by these factors measured by this system. Thesis advisor: Yoichi Ando Copies of this thesis written in English can be obtained from Masatsugu Sakurai, Yoshimasa Electronic Inc., Daiichi-Nishiwaki Bldg., 1-58-10 Yoyogi, Shibuya, Tokyo, 151-0053 Japan. E-mail address: saku@ymec.co.jp.