Making outdoor public announcements intelligible at anytime by dispersal arrangement of loudspeakers

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04807
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 23020:Architectural environment and building equipment-related
• Research Institution: Kobe University
• Principal Investigator: Sato Hayato 神戸大学, 工学研究科, 准教授 (30346233)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 防災行政無線 / 屋外拡声システム / 実測調査 / 幾何音響シミュレーション / 音声了解度

Outline of Final Research Achievements

The following studies (1) to (3) were conducted in order to obtain basic data for designing a dispersal arrangement of loudspeakers to stabilize the quality of outdoor public notification systems providing disaster prevention information. (1) A long-term measurement survey was conducted on existing outdoor public notification systems, and the results served as an illustrative example of the relationship between the distance from the loudspeaker and the variation of the sound pressure level. (2) Listening experiments were conducted using existing warning alarm sounds, and the results showed that a sound pressure level of about 65 dB is necessary to create a sense of urgency. (3) Geometric-acoustic simulations were conducted in an urban area, and the advantages of placing the loudspeaker as high as possible and using the road as a sound propagation path were summarized based on the results.

Free Research Field

環境音響学

Academic Significance and Societal Importance of the Research Achievements

本研究の成果は，屋外拡声システムのスピーカの分散配置の設計に不可欠な基礎情報を提供するものである。具体的には，本研究によって示された拡声音の必要最小限の音圧レベルの目安と，スピーカからの距離による音圧レベルのばらつきの実測事例は，それぞれのスピーカから再生する音の音圧レベルを十分な安全マージンを持って設計するための基礎資料となる。また，都市街区でのスピーカ配置の最適化事例も今後新設・増設される屋外拡声システムの参考資料となる。これらは社会的には災害に強い社会基盤の実現に貢献するものである。また，学術的には蓄積の少ない屋外における音声の長距離伝搬に関する貴重なデータとして資するものである。