This paper investigates the noise inside a metro coach running through the most recent tunnel of Cairo. The study focuses on the effects of alignment profiles on the A-weighted noise level. Although the latest line has not been studied yet, noise levels inside the old lines attracted the attention of researchers due to their importance as the first mass transit system in Africa. Given that windows are usually kept open, measurements were conducted inside the empty cabin at the end of the train with open windows according to ISO 3381:2005. Results showed that noise emissions inside the running coaches are high and do not follow either international or general national legislation, which presents health hazards for drivers and commuters. Speech intelligibility is required for train radio units and driver consoles for voice communications, which provides a safe working environment for the train crew. The present study reveals that tight curves mainly contribute to high noise. The noise levels are further raised by the reflective surface of the tunnel with a circular cross-section and the unballasted track. Moreover, the noise level is affected by the location of the coach and window conditions (open/close) to some extent.

本文调查了地铁客车穿过开罗最近的隧道时的噪音。该研究侧重于对齐配置文件对 A 加权噪声水平的影响。尽管尚未研究最新的线路，但旧线路内部的噪音水平由于其作为非洲第一个公共交通系统的重要性而引起了研究人员的注意。鉴于窗户通常保持打开状态，根据 ISO 3381:2005，在火车末端的空舱内进行测量，窗户打开。结果表明，运行中的教练车内的噪音排放量很高，并且不符合国际或一般国家立法，这对司机和通勤者的健康构成危害。用于语音通信的列车无线电装置和驾驶员控制台需要语音清晰度，为列车乘务员提供安全的工作环境。目前的研究表明，紧密的曲线主要导致高噪声。具有圆形横截面的隧道的反射面和无砟轨道进一步提高了噪音水平。此外，噪音水平在一定程度上受客车位置和窗户状况（开/关）的影响。