Objective and subjective differences between adjacent seats in a multipurpose hall

Abstract

The purpose of this study was to evaluate differences between adjacent seats in terms of objective measures and subjective perception based on measurements and recordings taken in a mid-sized multipurpose hall. The work is based on the hypothesis that minimal differences should be found between nearby seats. Measurements were taken in three groups of nine adjacent seats. The differences between seats were analyzed in terms of the number of just noticeable differences (JNDs), using 1 dB for strength (G), 5% for early decay time (EDT) and 1 dB for clarity index (C80). The average differences between adjacent seats within a given group were approximately 2.5 JNDs for G, 4 JNDs for EDT and 2.5 JNDs for C80, which implies that these differences might be audible. However, these differences may be within measurement error. Differences in late lateral energy level (GLL), a measure of listener envelopment (LEV), were all less than 1 dB. A total of 35 test subjects were presented binaural recordings from two seat groups and were asked to evaluate LEV and acoustical quality. In general, subjects did not perceive differences between the recordings as hypothesized, with the exception of two cases where differences in LEV were statistically significant.