Risks of Ear Complaints of Passengers and Drivers While Trains Are Passing Through Tunnels at High Speed: A Numerical Simulation and Experimental Study.

Pengpeng Xie,Honghao Zhang,Yong Peng,Tiantian Wang

doi:10.3390/ijerph16071283

Abstract

Ear complaints induced by interior pressure transients are common experiences for passengers and crew members when high-speed trains are passing through tunnels. However, approaches to assessing the risks of the pressure-related aural discomfort have not been reported until recently. The objective of this study was to evaluate the hazards of interior pressure transients of high-speed train on human ears combining the effects of operation speed and seal index. Moving model tests were conducted to obtain the pressure transients when the model train runs in the tunnel. The recorded data were transformed into the interior pressures by empirical formula. Furthermore, the aural sensations were divided into four levels hierarchically and the range for each level was derived by logistic regression analysis method and represented by three biomechanical metrics. Furthermore, a human middle ear finite element (FE) model was used to simulate its dynamics under the interior pressures. The results indicate that lifting operation speed from 250 km/h to 350 km/h in tunnel will prolong the duration of ear complaints by more than two times whereas improving the seal index from 4 s to 12 s will reduce the incidences of the onset of tinnitus and hearing loss by more than ten times. In addition, the duration of aural comfort shortens from the head car to the tail car against the running direction. It is desirable that enhancing the seal index improve the aural sensations of the passengers and crew members considering the lifting operation speed of high-speed train.

Highlights

Due to the interactions between air, rail and train, a wide variety of concerns have emerged relating to aerodynamic noise, resistance, environmental and public health issues [1,2]
This study proposed a kind of biomechanical approach to predict the potential aural sensations that passengers and crew members may experience in a tunnel during travel by train
The stapes footplate (SFP) is connected to the oval window of the inner ear which is composed of vestibular semi-duct and cochlea, the vibration input from the oscillation of the tympanic membrane (TM) is transmitted to the inner ear and in turn elicits movement of both vestibular semi-duct and cochlea

Summary

Introduction

Due to the interactions between air, rail and train, a wide variety of concerns have emerged relating to aerodynamic noise, resistance, environmental and public health issues [1,2]. The interactions intensify when high-speed trains pass through a tunnel. This simultaneously gives rise to pressure fluctuations inside the train, which cause aural discomfort in the passengers and crew members [3]. In China, a large number of tunnels have been constructed ranging from hundreds of meters to tens of kilometers in length. For train drivers with long years of service. Res. Public Health 2019, 16, 1283; doi:10.3390/ijerph16071283 www.mdpi.com/journal/ijerph

Objectives

Methods

Results

Discussion

Conclusion