## Reverberation Time - The Mother of All Acoustic Parameters

Magne Skålevik, Senior rådgiver

Brekke & Strand akustikk AS

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msk@bs-akustikk.no | www.bs-akustikk.no | www.akutek.info

Abstract: Wallace Sabine introduced the reverberation time (RT) as a measure of acoustic conditions in rooms a century ago. After some decades of experience with RT it became evident that two rooms with similar RT could still be sounding differently. Until today, a large number of different parameters have been suggested to describe these differences. In an attempt to settle for a limited number of listener’s aspects, and a limited number of physical measures associated with each of them, a set of five aspects have been suggested. In the ISO standard 3382-1, the RT is not included in the group of physical measures associated with listener’s aspects. It is tempting to jump to the conclusion that the reverberation time era has come to an end. However, from statistical analysis of measurements and computer simulations, and from Barron’s Revised Theory it can be shown that RT is the underlying acoustical parameter governing 4 out of the 5 listener’s aspects included in ISO 3382-1. Besides, if any acoustician where allowed to ask for only one single number in order to obtain information about the acoustics of a concert hall, it would most certainly be the mid-frequency RT.