Abstract
The sound strength G is a room acoustical parameter used to investigate the sound distribution in a hall or to compare the loudness between different halls. ISO 3382-1 describes several methods to measure G. The accuracy of a G measurement depends on the accuracy with which the power level of the sound source can be determined or with which the measurement system can be calibrated. In this research the different available sound strength calibration methods have been compared using a standard omnidirectional (dodecahedron) sound source. Using the same measurement equipment, different (system) calibration methods are compared: 1] free-field measurement in an anechoic room, 2] sound intensity measurement in an anechoic room, 3] diffuse-field measurement in a reverberation
room, 4] near-field measurement on stage in a concert hall. For method 1, measurements have been performed in a horizontal plane with white noise and exponential sweeps at various distances from the sound source. For method 2,
intensity measurements according to ISO 9614-3 have been performed using white noise while scanning the sound source surface with a two microphone probe. For method 3, the direct method and the comparison method according to the ISO 3741 standard have been used to determine the sound power level using white noise. Also, a system calibration has been performed in the anechoic room and the reverberation room using exponential sweeps. Finally, for method 4, a convenient near-field measurement method at a distance of 1 m has been performed on the stages of a large and a small concert hall using white noise and exponential sweeps. It has been found that the intensity and the diffuse-field calibration methods give substantially equal results. The horizontal-rotation free-field calibration method
gives results that differ significantly from those of the diffuse-field and intensity methods. For a survey G measurement in a concert hall it is sufficient to perform an on-site calibration.
Original language | English |
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Title of host publication | Proceedings of 20th International Congress on Acoustics, ICA 2010 |
Place of Publication | Sydney |
Publisher | Australian Acoustical Society |
ISBN (Print) | 978-0-646-54052-8 |
Publication status | Published - 2010 |
Event | conference; ICA 2010 Sydney, Australia; 2010-08-23; 2010-08-27 - Duration: 23 Aug 2010 → 27 Aug 2010 |
Conference
Conference | conference; ICA 2010 Sydney, Australia; 2010-08-23; 2010-08-27 |
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Period | 23/08/10 → 27/08/10 |
Other | ICA 2010 Sydney, Australia |