5pAA1. Acoustical measurements in occupied halls.

Session: Friday Afternoon, December 6

Time: 2:00

Author: Dana L. Kirkegaard
Location: Kirkegaard Acoustics, Inc., 4927 Wallbank Ave., Downers Grove, IL 60515


The presence of musicians and audience may cause significant changes in the reflection structure and the reverberation of a hall. This is particularly true in halls with sound reflective seating, e.g., Boston Symphony Hall. Occupied hall measurements require a minimally intrusive stimulus that is capable of achieving a high signal/noise ratio despite the background noise of the audience. A series of experiments were conducted to determine listener preferences and signal/noise ratios for various measurement stimuli, source levels, and number of averages. Stimuli included various swept sine, noise, maximum length sequence (MLS), and pulse signals. Background noise of the audience was simulated using loudspeakers. The level and spectrum were determined by measurements of background noise in occupied halls. Results indicate that the MLS stimulus, which is widely used for unoccupied hall measurements, is problematic for occupied hall measurements. This research has practical application in conducting occupied hall measurements.

ASA 132nd meeting - Hawaii, December 1996