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http://dx.doi.org/10.5050/KSNVE.2015.25.7.462

Characteristics of Acoustic Indicators Evaluating Speech Intelligibility in Korean Elementary School Classrooms  

Lee, Seong-Bok (Department of Architectural Engineering, Graduate School of University of Seoul)
Kim, Myung-Jun (Department of Architectural Engineering, University of Seoul)
Yang, Hong-Seok (Land and Housing Institute, Land and Housing Corporation)
Publication Information
Transactions of the Korean Society for Noise and Vibration Engineering / v.25, no.7, 2015 , pp. 462-469 More about this Journal
Abstract
This study was carried out to examine characteristics of various acoustic indicators evaluating speech intelligibility such as reverberation time(T30), D50, C50 and speech transmission index(STI) in Korean elementary school classrooms. Results showed that mean T30 at middle frequencies(500 Hz to 2000 Hz) measured in 9 classrooms was about 0.75 s, which exceeds a regulation specified on American National Standards(ANSI); 0.60 s. Mean D50, C50 and STI were 60 % to 66 %, +2 dB to +3 dB, and 0.65, respectively. The maximum difference in D50 and C50 according to different receiver points in a classroom was 13 % and 2.5 dB, while the maximum difference in T30 was 0.03 s. Whereas STI measured in classrooms has relatively low correlation with other indicators, correlation between D50 and C50 was high, R2=.9964. In addition, T30 and C50 were fitted well as logarithmic regression curve with R2=.9610. It was +3.73 dB in C50 and 68 % in D50 which are the value corresponding to 0.60 s in T30 on this curve.
Keywords
Classroom Acoustics; Acoustic Indicator; Speech Intelligibility; Reverberation Time; $D_{50}$; $C_{50}$; Speech Transmission Index;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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