Measurement of the quantity of sound energy returned to stage positions within a nominated period

Abstract

Further to a paper presented at the 96th Meeting of the ASA [J. Acoust. Soc. Am. 64, S171(A) (1978)], in which a method for measuring the attack sequences and the spread of attack of musicians playing in ensemble was presented, a method has been developed for measuring the quantity of sound energy returned to stage positions within a nominated period of time. Hence, if a spread of attack of 80 ms is considered to be a clean attack, a measure of sound energy returned to stage positions within a period of 80 ms might be of value in assessing the comparative ease with which musicians can play in ensemble in various halls. In measuring the quantity of sound energy returned to stage positions in five Australian auditoria, a gated signal was emitted from an isotropic sound source, the SPL of the signal was calibrated to be 100 dB linear SPL at a distance of 0.4 m from the sound source, signals emitted were pure tones of frequencies 250, 500, 1000, and 2000 Hz. The sound energy returned was displayed on a CRO screen which enabled the sound energy returned to each position on each stage, to be measured.