Chamber music hall acoustics: Measurements and perceptual differences.

This study investigates the room acoustics of seven chamber music halls of various modern and historical architecture by means of objective room acoustic measures and a subjective listening experiment. The acoustic measurements were performed with heavy cloth covering the audience areas to simulate occupancy in the halls. A loudspeaker quartet was used for auralizations, which were reproduced in a surrounding loudspeaker array. The perceptual differences between the halls were evaluated in terms of envelopment, warmth, clarity, proximity, and preference by using a paired comparison paradigm. The subjective evaluations were conducted in two different laboratories and latent class analysis was used to study the agreement between laboratories and the emergence of different listener groups in the ratings of each attribute. Concerning preference, the emergence of two groups found in the study of large symphony halls was confirmed, where one group prefers rich, enveloping sound and one group prefers high clarity. The perceptual ratings were not clearly associated with a specific hall shape, but rather depended on the distribution of early and late sound energy. Thus, the distinction between rectangular and non-rectangular floor plans previously found for large symphony halls was not observed with these smaller halls.

Predicting the perceived reverberation in different room acoustic environments using a binaural auditory model.

In this paper a binaural auditory model was used to compute reverberance estimates in four simulated halls. For three of the halls different absorption conditions were evaluated. The model estimates (pRev) were obtained using music excerpts of an orchestra consisting of 23 instrument sections and then compared with the room acoustic parameters of reverberation time (T30) and early decay time (EDT) at mid frequencies. Although the results showed that pRev has a higher correlation with EDT rather than with T30, this relationship depends on the properties of the instruments. The simulations show that pRev depends on the presentation level and that for instruments with similar critical-band spectrum, pRev follows a similar trend across acoustic conditions. A computational framework and sound stimuli are provided to encourage the search of experimental evidence of the aspects addressed in this study.

Spatial analysis and auralization of room acoustics using a tetrahedral microphone.

A compact tetrahedral microphone array is used to measure several controlled sound fields and compare the analysis of spatial room impulse responses with two methods: spatial decomposition method (SDM) and IRIS, a commercial system based on sound intensity vector analysis. Results suggest that the spatial accuracy of both methods is similar and in most cases the error is comparable to the localization uncertainty of human listeners. Furthermore, a listening test is conducted comparing three 3D-sound fields and their SDM auralizations. Results suggest that the similarity of the auralized and original sound fields depends on the target room and stimulus.