Characteristic of room acoustical parameters with source-receiver distance on platform in subway stations

Suhong Kim; Eunsung Song; Jeonghoon Kim; Songmi Lee; Jongkwan Ryu

doi:10.7776/ASK.2021.40.6.615

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2021 Vol.40, Issue 6 Preview Page Next Page

Research Article

Characteristic of room acoustical parameters with source-receiver distance on platform in subway stations 지하철 승강장의 음원-수음점 거리에 따른 실내음향 평가지수 특성

30 November 2021. pp. 615-625

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Abstract

Prior to proposing appropriate standard for subway station platform, this study conducted field measurements to examine characteristics of room acoustics on platform of two subway stations. As a result of analyzing the longitudinal length of the platform, Sound Pressure Level (SPL) decreased (maximum difference : 14 dB), Reverberation Time (RT) tended to increase (maximum difference of 0.8 s ~ 1.5 s), and C50 and D50 were decreased (maximum difference: 5.9 dB ~ 9.1 dB and 31.8 % ~ 37.6 %, respectively) as measurement positions moved away from the sound source. The Interaural Cross-correlation Coefficient (IACC) did not show clear tendency, but it was lower than 0.3 in entire points. It is judged that the subway platform has non-uniform sound field characteristics due to various combinations of direct and reflective sound even though it is finished with a strong reflective material.This indicates that the room acoustic characteristics of the near and far sound field are clearly expressed depending on the source-receiver distances in the subway platform having a long flat shape with a low height compared to the length.Therefore, detailed architectural and electric acoustic design based on the characteristics of each location of speaker and sound receiver in the platform is required for an acoustic design with clear sound information at all positions of the platform.

Keywords

Subway station

Platform

Room acoustical parameters

Reverberation time

본 연구에서는 지하철 승강장에 적합한 실내음향 설계기준 제시에 앞서, 현재의 지하철 승강장의 위치별 실내음향 특성을 파악하기 위해 2개의 지하철 역사 승강장에서 현장 측정을 실시하였다. 승강장의 길이방향에 따른 분석 결과, 음원에서 수음점이 멀어질수록 음압레벨은 감소(최대 차이: 약 14 dB), 잔향시간은 증가하는 경향(최대차이: 0.8 s ~ 1.5 s)이었고, C₅₀과 D₅₀은 감소하는 경향(최대 차이: 5.9 dB ~ 9.1 dB와 31.8 % ~ 37.6 %)인 것으로 나타났다. 공간감의 지표인 Interaural Cross-correlation Coefficient(IACC)는 음원과의 거리에 따른 명확한 경향성은 보이지 않았지만, 전체적으로 0.3이하의 낮은 값을 보였다. 이러한 결과를 살펴보았을 때 지하철 승강장은 일반적으로 강한 반사재로 마감 되었음에도 수음위치에 따라 직접음과 반사음의 다양한 조합이 형성되어 비균일한 음장특성을 갖는 것으로 판단된다. 이는 길이 대비 높이가 낮고 긴 평면형태를 갖는 지하철 승강장에서는 음원과 수음점의 거리에 따라 근접음장과 원음장의 실내음향특성이 뚜렷이 발현되고 있음을 나타난다. 따라서, 승강장의 모든 위치에서 명료한 음정보를 갖춘 실내음향설계를 위해서 승강장에서의 스피커와 수음점 위치별 특성에 기인한 세부 건축 및 전기음향설계가 필요하다.

키워드

지하철 역사

승강장

잔향시간

실내음향 파라메터

References

Public Trans-portation Report in 2020, https://www. kotsa.or.kr/ptc/inside_use.do, (Last viewed November 12, 2021).

Current State of Information Related to the Weak Pedestrians and Mobility Facilities in Transportation Safety Information Management System, https://tmacs. kotsa.or.kr/, (Last viewed June 20, 2021).

J. Tardieu, P. Susini, F. Poisson, P. Lazareff, and S. McAdams, "Perceptual study of soundscapes in train stations," Applied Acoustics, 69, 1224-1239 (2008). 10.1016/j.apacoust.2007.10.001

S. Yılmazer and D. Dalirnaghadeh, "The effect of soundscape on memory performance in a wayfinding task in a virtual outpatient polyclinic," Proc. INTER- NOISE and NOISE-CON Cong. and Conf. 3254-3263 (2020).

J. Han, S. B. Kwon, and C. Chun, "Indoor environment and passengers' comfort in subway stations in Seoul," Building and Environment, 104, 221-231 (2016). 10.1016/j.buildenv.2016.05.008

H. S. Song, J. H. Kim, S. M. Lee, S. H. Kim, and J. K. Ryu, "A survey on the signal and guide sound in subway station for the elderly," Proc. KSNVE. 76-76 (2020).

Ministry of land, infrastructure and transport, "Design criteria for railroad," Tech. Rep., 2015.

H, Sato, H. Sato, M. Morimoto, and R. Ota, "Acceptable range of speech level for both young and aged listeners in reverberant and quiet sound fields," J. Acoust. Soc. Am. 122, 1616-1623 (2007). 10.1121/1.276678017927421

H. Sato, H. Sato, and M. Morimoto, "Effects of aging on word intelligibility and listening difficulty in various reverberant fields," J. Acoust. Soc. Am. 121, 2915-2922 (2007). 10.1121/1.271371517550189

N. Hodoshima, T. Arai, and K. Kurisu, "Intelligibility of speech spoken in noise/reverberation for older adults in reverberant environments," Proc. ISCA. 1464-1467 (2012). 10.21437/Interspeech.2012-415

Y. H. Kim and Y. Soeta, "Effects of reverberation and spatial diffuseness on the speech intelligibility of public address sounds in subway platform for young and aged people," Proc. Meetings on Acoustics, 19, 050061 (2013). 10.1121/1.4798974

J. Kang, Acoustics of Long Spaces: Theory and Design Guidance (ThomasTelford, sheffield, 2002), pp. 77.

J. Kang, "Acoustics in long enclosures with multiple sources," J. Acoust. Soc. Am. 99, 985-989 (1996). 10.1121/1.414627

Y. Wu, J. Kang, and W. Zheng, "Acoustic environment research of railway station in China," Energy Procedia, 153, 353-358 (2018). 10.1016/j.egypro.2018.10.038

R. Shimokura and Y. Soeta, "Train noise and sound field characteristics in underground station," Proc. 4^th ISTD. 49-52 (2009).

S. W. Lee, D. U. Jeong, S. Y. Lee, and S. G. Cha, "A study on the indoor noise levels in underground stations considering architectural design features" (in Korean). Architectural Institute of Korea, 18, 235-241 (2002).

S. W. Lee, D. U. Jeong, S. Y. Lee, S. G. Cha, and M. S. Sym, "A study on the evaluation of acoustic characteristic in underground subway stations in Seoul" (in Korean), JAIK. 19, 155-162 (2003).

M. J. Lee, H. W. Oh, and M. J. Kim, "Measurement and analysis on the noise by train cars at platform of subway station" (in Korean), JKLES. 6, 126-133 (2009).

J. S. Bradley, R. Reich, and S. G. Norcross, "A just noticeable difference in C50 for speech," Applied Acoustics, 58, 99-108 (1999). 10.1016/S0003-682X(98)00075-9

A. Sehr, E. A. Habets, R. Maas, and W. Kellermann, "Towards a better understanding of the effect of reverberation on speech recognition performance," Proc. IWAENC. 1-4 (2010).

L. G. Agustina, Design and optimisation of voice alarm systems for underground stations, (Ph. D, London South Bank University, 2012).

S. H. Kang, Fundamentals of Sound Engineering (Sound Media, Seoul, 2018), pp. 77.

W. S. Jr. Morrow, "The urban mass transportation," Tech. Rep., 1970.

Rail Transit Committee, "Noise and vibration; Guidelines and principles for design of rapid transit facilities," APTA(American public transit association), Tech. Rep., 1979.

R. Shimokura and Y. Soeta, "Sound field characteristics of underground railway stations-Effect of interior materials and noise source positions," Applied Acoustics, 73, 1150-1158 (2012). 10.1016/j.apacoust.2012.05.012

A. Avni and B. Rafaely, "Interaural cross correlation and spatial correlation in a sound field represented by spherical harmonics," Proc. Ambisonics Symposium, 823-828 (2009). 10.1121/1.327860520136205

Y. H. Kim and Y. Soeta, "Architectural treatments for improving sound fields for public address announcements in underground station platforms," Applied acoustics, 74, 1205-1220 (2013). 10.1016/j.apacoust.2013.05.001

IEC 60268-16, Sound System Equipment; Objective Rating of Speech Intelligibility by Speech Transmission Index, 2020.

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 : 40
No :6
Pages :615-625
Received Date : 2021-08-23
Revised Date : 2021-10-07
Accepted Date : 2021-10-28
DOI :https://doi.org/10.7776/ASK.2021.40.6.615

The Journal of the Acoustical Society of Korea ISSN:1225-4428(Print) 2287-3775(Online) 한국음향학회지

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