The Journal of the Acoustical Society of Korea (한국음향학회지)

The Acoustical Society of Korea (한국음향학회)
권호 표지
DOI QR코드

DOI QR Code

Interior surface treatment guidelines for classrooms according to the acoustical performance criteria

학교 교실의 음환경 기준에 따른 실내마감 방안

  • Received : 2015.09.03
  • Accepted : 2015.12.23
  • Published : 2016.03.31
Download PDF
⟨ Previous Next ⟩

Abstract

There are many results in which acoustical conditions of a classroom play an important role for studying effects and academic achievement of students. However, there are very few guidelines or design proposals which could make appropriate acoustic environment when classrooms are built or renovated. The present study suggests various design proposals satisfying acoustic standards of classrooms based on theoretical calculation and acoustic field experiments. At first, minimum area of sound absorption was calculated which is required to satisfy the acoustic standard for domestic middle and high schools. Also, room acoustic measurements were carried out in order to investigate the acoustic performance of an existing classroom by changing interior finishing materials on ceiling and rear walls. As a result, it was revealed that reverberation time standard below 0.8 s can be acquired even if there is no sound absorption on ceiling which is a general practice executed in Korea. Specially, it was found that if partial area of ceiling would be treated as reflective with the ratio of sound absorption and reflection as 2:1, almost similar acoustic parameters of $C_{50}$, $D_{50}$, RASTI (Rapid Speech Transmission Index) and higher sound levels could be acquired in comparison with the case of entire sound absorption on ceiling.

교실 음환경은 학생들에게 매우 중요한 요소로 학습효과와 학업 성취에 매우 큰 영향을 미친다는 연구결과가 다수 발표되고 있다. 그러나 학교 교실의 신축이나 리모델링 시에 가이드라인 및 설계방안이 제시된 바 없어 적절한 음환경을 실현하는데 큰 어려움을 겪고 있다. 따라서 본 연구에서는 이론적 수식과 현장실험을 통하여 교실의 음환경 기준을 만족하기 위한 다양한 설계방안을 제시하고자 한다. 이를 위해 국내 중 고등학교의 교실에서 실내음향성능 기준을 만족하기 위해 필요한 최소 흡음면적을 계산하였다. 또한 교실의 천장 및 뒷벽의 다양한 마감상태에 따른 실내음향성능을 알아보고자 현장실험을 진행하여 실험 결과를 비교 분석하였다. 연구 결과, 국내 교실 천장에 현재 거의 모든 학교에서 시행하고 있는 것처럼 천정흡음재를 설치하지 않아도 잔향시간 기준인 0.8 s를 만족할 수 있는 것으로 나타났다. 특히, 천장 일부 면적에 반사재를 적용하되 면적의 비율이 흡음 2 : 반사 1이면서 가로로 구획하는 것이 음압레벨을 향상시키며 전체가 흡음인 경우와 비슷한 명료도[$C_{50}$, $D_{50}$, RASTI(Rapid Speech Transmission Index)]를 확보할 수 있다.

Keywords

References

  1. ANSI/ASA S12.60, Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools - Part 1: Permanent Schools, American National Standard (2010).
  2. Building Bulletin 93, Acoustic Design of Schools ; The Department for Education and Skills (2011).
  3. C. J. Park, D. J. Ryu, J. Y. Kyoung, and C. H. Haan, "Analysis of the acoustic performance of classrooms in Korea" (in Korean), J. Acoust. Soc. Kr. 33, 317-326 (2014).
  4. J. H. Jung, "Design criteria for the implementation of good classroom acoustics research and improvement" (in Korean), Fire protection technology 42, 17-25 (2007).
  5. C. J. Park, Establishment of the acoustical performance criteria for middle and high school classrooms (in Korean), (Ph.D. thesis, Chungbuk National University, 2014).
  6. M. Long, Architectural Acoustics (Academic Press, United States, 2005), pp. 607.
  7. S. R. Bistafa and J. S. Bradley, "Predicting reverberation times in a simulated classroom," J. Acoust. Soc. Am. 108, 1721-1731 (2000). https://doi.org/10.1121/1.1310191
  8. H. Sato and J.S. Bradley, "Evaluation of acoustical conditions for speech communication in working elementary school classrooms," J. Acoust. Soc. Am., 123, 2064-2077(2008). https://doi.org/10.1121/1.2839283
  9. C. J. Park and C. H. Haan, "Effect of the inter-aural level differences on the speech intelligibility depending on the room absorption in classrooms" (in Korean), J. Acoust. Soc. Kr. 32, 335-345 (2013). https://doi.org/10.7776/ASK.2013.32.4.335
  10. D. U. Jeong, Y. K. Oh, and H. K. Chu, "Spatial distribution of early reflections and speech intelligibility" (in Korean), J. Archi. Inst. Kr. Suppl. 1(s) 21, 537-540 (2001).
  11. Y. J. Choi, "The measurements and evaluations on the configurations of absorptive and diffusing treatments in classrooms using a scale model" (in Korean), J. Kr. Inst. Educat. Facili. 20, 37-44 (2013). https://doi.org/10.7859/kief.2013.20.1.037
  12. H. Kuttruff, Room Acoustics (Applied Science Pub.Ltd., London, 1973), pp. 239.
  13. S. B. Shin, Enhancement of the sound clarity in lecture rooms using absorptive and diffusive materials (Master thesis, Chungbuk National University 2007).
  14. M. D. Egan, Architectural Acoustics (J. Ross Publishing Classics, Florida, 2007), pp. 52-53.
  15. Skyviva, http://okviva.co.kr/, 2011.
  16. D. J. Ryu, C. J. Park, and C. H. Haan, "Interior finishing plan of the school classrooms according to the acoustical Performance criteria" (in Korean), J. Acoust. Soc. Kr. Suppl.2(s) 33, 80-86 (2014).