An interlaboratory round robin test to measure a hall’s reverberation time is performed using different equipment employed by 17 professional participants. All common measuring methods are represented: direct recording of impulse responses using impulse sound sources, indirect impulse response generation using software, and recording interrupted noise. Systematic differences are detected between these methods. Scatterings in measurement results are generally low, and, compared to previous studies, standard deviation is similar however some participants clearly differed in performance from others. The interrupted noise method shows the largest data scatter. Reverberation time specified as a single value shows large differences because the number is determined in a variety of ways. A revision of ISO 3382 is recommended.
Authors: Markus Zehner (www.zehner.ch), Daniel Zurwerra (Virtually Audio GmbH) and Andrew Goldberg (Independent)