We have developed a new diagnostic system entitled "Diagnostic System for Sound Fields", which can measure orthogonal factors and calculate subjective attributes of sound fields.All the functions of the Realtime Analyzer Light ,Realtime Analyzer IPR and Realtime Analyzer ACF are included in the Diagnostic System for Sound Fields 3.1. Based on the model of auditory-brain system which consists of the autocorrelation mechanism, the interaural crosscorrelation mechanism between the both auditory pathways, and the specialization of human cerebral hemispheres [Ando, Architectural Acoustics, Blending Sound Sources, Sound Fields, and Listeners. AIP Press/Springer-Verlag, New York, 1998], the new diagnostic system was developed. The system works on PC for Windows, and it is no need for special additional devices. After obtaining the impulse response, four orthogonal factors including the SPL, the initial time delay gap between the direct sound and the first reflection, the subsequent reverberation time and the IACC are analyzed for the calculation of the scale values of global and individual subjective preference. In addition to the four factors, two more factors, tIACC and WIACC, in the interaural crosscorrelation function are figured out for evaluating the image shift of sound source and the apparent source width (ASW), respectively. Also, the effective duration, te, and fine structures of autocorrelation function of sound signals including the value of first maximum, f1 and its delay time t1 are analyzed. Keeping the subjectively optimal condition, this system may be utilized for automatic control of sound fields by electroacoustic systems.

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