2aAA2. Sound absorption of occupied chairs as a function of chair design and audience clothing.

Session: Tuesday Morning, May 14

Time: 9:05

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


In 1989, a series of experiments was initiated at Riverbank Acoustical Laboratories to study the detailed relationships between chair design and audience absorption. Chairs were measured occupied and unoccupied. Many chairs were disassembled and tested as individual chair components to confirm specific correlations between design and data. Chair manufacturers responsed by redesigning chairs for further testing. Each series of tests was designed to minimize the number of experimental variables. An unupholstered reference chair provided a baseline for each series of occupied tests. The baseline measurements provide a means of comparing occupied chair measurements made with different occupants and/or changes of clothing. They also establish baseline absorption values for an audience in minimally absorptive chairs. Results of these occupied chair measurements show that differences in chair design are most highly correlated with data below 500 Hz, which ranged from 2 to 8 Sabins/person. Above 500 Hz, data ranged from 6 to 11 Sabins/person as a function of chair design and seasonal changes in occupants' clothing. Results support the hypothesis that chair design and seasonal clothing are critical in concert halls and other rooms with low residual absorption. [Research supported by Irwin Seating, JG Seating and Country Roads.]

from ASA 131st Meeting, Indianapolis, May 1996