Railway transportation acoustics

Although the rail system is widely credited with its environmental strengths, noise still appears to be its Achilles heel, despite undeniable progress in the case of high-speed trains, for example.

Research into rail noise has already made it possible to identify and reduce rolling noise, the main source of rail noise at conventional passenger speeds. It is vital that similar progress is made in rail freight operations. Similarly, peri-urban traffic in major conurbations, and particularly in the Ile-de-France region, must also benefit from this progress if it is to continue to develop, given the high density of housing along railway platforms.

The problem of noise – as illustrated by the example of rolling noise – is that of a system in which all components (the vehicle wheel and the infrastructure rail) contribute to the emission. "The effectiveness of solutions depends on simultaneous action on all the components of this system." (Extract from the editorial by Chairman Louis Gallois in the Revue Générale des Chemins de Fer, October 2003).

While the above-mentioned rolling noise remains predominant up to around 300 km/h, aerodynamic noise makes a significant contribution at higher speeds, firstly because, by reducing rolling noise, aerodynamic noise appears earlier, and secondly because aerodynamic noise increases more rapidly with speed.

These various sources of environmental noise also affect the comfort of passengers and locomotive engineers. Occasional sources such as air-conditioning noise, audible announcements, cell phones, loud passenger conversations, etc., can cause additional discomfort, which is obviously a physiological issue, but also a psychoacoustic one.