ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

3aAA4. Technical matters relating to the measurement of interaural cross-correlation (IACC) coefficients in concert halls and opera houses.

Takayuki Hidaka

Toshiyuki Okano

Takenaka Res. & Dev. Inst., 5, 1-chome, Ohtsuka, Inzai-machi, Inba-gun, Chiba 270-13, Japan

The interaural cross-correlation coefficient (IACC) has been shown to be an important measure, along with others, of the quality of acoustics in concert halls and opera houses [Schroeder et al., 1199 (1974); Ando, Concert Hall Acoustics (Springer-Verlag, Berlin, 1985)]. When measured in auditoriums with binaural heads (real or dummy) using an impulse source, means must be adopted to achieve accuracy and precision, and to select the type of impulse and processing methods to make IACC most useful in the prediction of acoustical quality. Subjects covered include: (1) type of impulse, (2) convolution signal, (3) integration limits, (4) directivity and positions of source in the hall, (5) parameters of head, (6) comparisons of measurements made with real and dummy heads, (7) value of torso, (8) measuring positions in hall, (9) comparison of measurements of IACC in halls with upholstered and nonupholstered seats, (10) comparison with IACC measurements made by other laboratories, and (11) some preliminary data on differences among IACCs measured in occupied and unoccupied halls.