Browse > Article
http://dx.doi.org/10.22805/JIT.2021.41.1.015

Proposing a simple procedure for predicting the acoustical conditions in occupied classrooms from the measured unoccupied values  

Ahn, Jae-Young (Samwoo ANC Acoustics & Noise Consulting, Research Fellow)
Choi, Young-Ji (Department of Architectural Engineering, Kangwon National University)
Publication Information
Journal of Industrial Technology / v.41, no.1, 2021 , pp. 15-20 More about this Journal
Abstract
This work proposes a simple method to use the added absorption per person values to predict the expected values of the acoustical conditions in occupied classrooms. This method is based on the effects of the values of added absorption per person on the unoccupied total absorption values of the classrooms and on other room acoustical parameters. The total sound absorption in an unoccupied classroom can be calculated from measured reverberation times in the classroom. The expected occupied absorption can be calculated using equation which was obtained in a previous study (Choi, 2017) by fitting a linear regression line to a plot of total occupied absorption versus the corresponding unoccupied total absorption values measured in 12 university classrooms. The ratios of occupied-to-unoccupied sound absorption are used to predict increments in the values of acoustical parameters that result when occupants are added to the rooms.
Keywords
Occupants; Total room sound absorption; Classrooms; Acoustical parameters;
Citations & Related Records
연도 인용수 순위
  • Reference
1 ISO, 2003, Acoustics, Measurement of the reverberation time of rooms with reference to other acoustical parameters, ISO 3382.
2 HODSON M., 1999, Experimental investigation of the acoustical characteristics of university classrooms, Journal of Acoustical Society of America, 106 1810-1819.   DOI
3 CHOI Y.J., 2017, Predicting classroom acoustical parameters for occupied conditions from unoccupied data, Applied Acoustics, 127 89-94.   DOI
4 IEC 60268-16 Edition 4.0, 2011, Sound system equipment. Part 16: Objective rating of speech intelligibility by speech transmission index.
5 BRADLEY J.S., 2011, Using room acoustics measures to understand a large room and sound reinforcement system, Proceedings of the Institute of Acoustics, 33.
6 CHOI Y.J., 2016, Effect of occupancy on acoustical conditions in university classrooms, Applied Acoustics, 114 36-43.   DOI
7 CHOI Y.J., 2017, Comparison of two types of combined measures, STI, and U50, for predicting speech intelligibility in classrooms, Archives of Acoustics, 42 527-532.   DOI
8 DIRAC room acoustics software version 6.0, 2014, Bruel & Kjaer, Denmark.
9 BRADLEY J.S., CHOI Y.J., JEONG D.U., 2013, Understanding chair absorption characteristics using the perimeter-to-area method, Applied Acoustics, 74 1060-1068.   DOI