All Issue

2026 Vol.45, Issue 2 Preview Page

Research Article

Towards classroom acoustic standard in Korea considering occupied acoustic conditions

재실 음향 특성을 반영한 국내 교실 음향 기준 제안

Young-Ji Choi1*
최 영지1*
1강원대학교 건축공학과
*Corresponding Author
31 March 2026. pp. 163-174
PDF XML Citation
Abstract

This study aims to provide data for establishing acoustic standards in Korean school classrooms by analyzing the results of an acoustic survey conducted in 49 classrooms and lecture rooms across elementary, junior high, high schools, and universities, totaling 106 active classes. The findings indicate that in spaces where speech intelligibility is critical, acoustic design should not be limited to unoccupied room conditions but must incorporate occupied conditions reflecting students and teaching activities to ensure adequate speech intelligibility. Based on the acoustic measurement results of classrooms and lecture rooms, the recommended reverberation time for spaces with a volume of 250 m3 or less is 0.60 s at 125 Hz – 4 kHz, with a range of 0.48 s to 0.72 s depending on the number of people in the room. To enable teachers to maintain an appropriate Speech to Noise Ratio (SNR) value without unnecessarily raising their voice levels during class, the maximum noise level in an unoccupied room is LAeq ≤ 40 dBA (the air conditioner is running). To minimize noise from adjacent classrooms during class activities, the wall's sound insulation performance should be STC ≥ 50 for adjacent classrooms and STC ≥ 45 for adjacent corridors. In areas where speech privacy is important, such as in a combined wall with a corridor, the STC should be ≥ 50. To achieve a speech intelligibility of Speech Transmission Index (STI) ≥0.60 and U50 ≥4.1 dB, the recommended SNR value of ≥15 dBA, and a C50 of ≥4 dB should be met. In this study, only 5 % of the 106 classrooms were from special schools. Therefore, when establishing acoustic standards for educational facilities, it is necessary to consider not only general schools, but also special schools that require acoustic support.

Keywords
Occupied conditions
Speech and noise levels
Acoustic standards
Speech intelligibility
Background noise levels
Reverberation Time (RT)
Noise isolation

본 연구의 목적은 국내 초·중·고등학교 및 대학교에 위치한 총 49개 교실과 강의실, 106개 수업 현장에서 수행한 공실 및 재실 음향 측정 결과를 바탕으로 교육시설 음향 기준을 제정하기 위한 기초 자료를 마련하는 것이다. 연구 결과, 음성 전달이 중요한 공간에서는 공실 상태의 음향 기준에만 의존하지 않고, 재실자와 수업 활동을 반영한 재실 음향 설계를 고려해야만 적절한 음성 명료도를 확보할 수 있음을 확인하였다. 국내 교실 및 강의실의 실내 음향 측정 결과를 바탕으로, 체적 250 m3 이하의 공간에 대한 권장 잔향 시간은 재실 80 % 기준 125 Hz – 4 kHz 대역에서 0.60 s ≤ Tott가 적절하며, 실내 재실 상태에 따라 상하 20 % 범위인 0.48 s ≤ Tott ≤ 0.72 s가 허용 범위이다. 교사가 수업 시 목소리 레벨을 무리하게 높이지 않고 적정 음성대 소음 비(Speech to Noise Ratio, SNR)값을 유지하기 위해 공실 최대 허용 소음 레벨은 LAeq ≤ 40 dBA(공조기 가동 시)가 적절하다. 인접한 교실 간 수업 활동에 의한 소음을 차단하기 위해 벽체 간 차음 성능은 인접 교실 STC ≥ 50, 인접 복도 STC ≥ 45가 적절하며, 복도와 인접한 복합 벽체의 경우 음성 프라이버시가 중요한 장소에서는 STC ≥ 50이 적절하다. 음성전달지수(Speech Transmission Index, STI) ≥0.60에 상응하는 음성 명료도 U50≥ 4.1 dB를 성취하기 위해, 수업 중 재실 음향 상태가 권장값인 SNR ≥15 dBA를 만족한다면, C50≥ 4 dB(재실 기준)가 요구된다. 본 연구에서는 총 106개 수업 현장 중 특수학교는 5 % 미만의 수업만을 대상으로 하여, 향후 교육시설 음향 기준 제정 시 일반 학교뿐만 아니라 음향적 지원이 필요한 특수학교의 재실 음향 특성까지 반영된 기준을 함께 제시할 필요가 있다.

키워드
재실 음향
음성 및 소음 레벨
음향 기준
음성 명료도
배경소음
잔향시간(Reverberation Time, RT)
차음
References
1

ANSI/ASA 12.60-2010, Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools: Part 1. Permanent Schools, 2010.

2

Education Funding Agency, Building Bulletin 93- Acoustic Design of Schools: Performance Standards, 2015.

3

DIN 18041:2016, Acoustic quality in rooms – Specifications and instructions for the room acoustic design, DIN-Normenausschuss Bauwesen, 2016.

4

UNI 11532-2:2020, Internal Acoustical Characteristics of Confined Spaces — Design Methods and Evaluation Techniques — Part 2: Educational Sector, 2020.

5

A. Astolfi, L. Parati, D. D’Orazio, and M. Garai, “The new Italian standard UNI 11532 on acoustics for schools,” Proc. ICA, 7004-11 (2019).

6

M. Hodgson, “Experimental investigation of the acoustical characteristics of university classrooms,” J. Acoust. Soc. Am. 106, 1810-1819 (1999).

10.1121/1.427931
7

M. Hodgson, R. Rempel, and S. Kennedy, “Measurement and prediction of typical speech and background noise levels in university classrooms during lectures,” J. Acoust. Soc. Am. 105, 226-233 (1999).

10.1121/1.424600
8

B. Shield and J. Dockrell, “External and internal noise surveys of London primary schools,” J. Acoust. Soc. Am. 115, 730-738 (2004).

10.1121/1.1635837
9

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).

10.1121/1.2839283
10

J. S. Bradley and H. Sato, “The intelligibility of speech in elementary school classrooms,” J. Acoust. Soc. Am. 123, 2078-2086 (2008).

10.1121/1.2839285
11

B. Shield, R. Conetta, J. Dockrell, D. Connolly, T. Cox, and C. Mydlarz, “A survey of acoustic conditions and noise levels in secondary school classrooms in England,” J. Acoust. Soc. Am. 137, 177-188 (2015).

10.1121/1.4904528
12

G. E. Puglish, L. C. Cantor Cutiva, L. Pavese, A. Castellana, M. Bona, S. Fasolis, V. lolorenza, A. Carullo, A. Burdorf, F. Bronuzzi, and A. Astolfi, “Acoustic comfort in high-school classrooms for students and teachers,” Energy Procedia, 78, 3096-3101 (2015).

10.1016/j.egypro.2015.11.763
13

Y. J. Choi, “Effects of occupancy on acoustical conditions in university classrooms,” Appl. Acoust. 114, 36-43 (2016).

10.1016/j.apacoust.2016.07.010
14

E. Sala and L. Ranrala, “Acoustics and activity noise in school classrooms in Finland,” Appl. Acoust. 114, 252-259 (2016).

10.1016/j.apacoust.2016.08.009
15

Y. J. Choi, “Evaluation of acoustical conditions for speech communication in active university classrooms,” Appl. Acoust. 159, 107089 (2020) .

10.1016/j.apacoust.2019.107089
16

C. Visentin and N. Prodi, “Assessing sound levels of student activity in primary school classrooms,” Proc. FA/EuroNoise 2025, 3741-3744 (2025).

10.61782/fa.2025.0148
17

ISO 3382-Acoustics, Measurement of the Reverberation Time of Rooms with Reference to Other Acoustical Parameters, 2003.

18

Brüel & Kjær, https://www.bksv.com/en/about/history, (Last viewed, March 20, 2026).

19

ISO 16283-1:2014, Acoustics — Field Measurement of Sound Insulation in Buildings and of Building Elements-Part 1: Airborne Sound Insulation, 2014.

20

ISO 16283-2:2020, Acoustics — Field Measurement of Sound Insulation in Buildings and of Building Elements-Part 2: Impact Sound Insulation, 2020.

21

Measuring Systems for Sound & Vibration, https://sinus-leipzig.de/en/produkte/software/samurai, (Last viewed, March 20, 2026).

22

ISO 717-1, Acoustics-Rating of Sound Insulation in Buildings and of Building Elements-Part 1: Airborne Sound Insulation, 1996.

23

ISO 717-2:2013, Acoustics — Rating of Sound Insulation in Buildings and of Building Elements - Part 2: Impact Sound Insulation, 2013.

24

ASTM E413-10, Classification for Rating Sound Insulation, 2010.

25

ASTM E989-99, Standard Classification for Determination of Impact Insulation Class (IIC), 1999.

Information
  • Publisher :The Acoustical Society of Korea
  • Publisher(Ko) :한국음향학회
  • Journal Title :The Journal of the Acoustical Society of Korea
  • Journal Title(Ko) :한국음향학회지
  • Volume : 45
  • No :2
  • Pages :163-174
  • Received Date : 2026-01-28
  • Revised Date : 2026-03-03
  • Accepted Date : 2026-03-17
  • DOI :https://doi.org/10.7776/ASK.2026.45.2.163
Journal Informaiton The Journal of the Acoustical Society of Korea The Journal of the Acoustical Society of Korea
E-Book
  • scopus_JASK
  • ESCI_JASK
  • Google scholar_JASK
  • NRF
  • KOFST
  • KISTI Current Status
  • KISTI Cited-by
  • crosscheck
  • orcid
  • ccl
Journal Informaiton Journal Informaiton - close