This book contains the presentations given during the 9th International Workshop on Railway Noise (IWRN9) which took place in Munich/Feldafing, Germany, on 4th to 8th September 2007. This workshop was organised by the Acoustics and Vibration Department of DB Systemtechnik, the technical engineering office of Deutsche Bahn AG. More than 120 participants from 17 countries followed the invitation to the wo- shop. This great response showed the continuing interest in an important topic of railway technology and offered the opportunity to present the recent results of intense worldwide activities to the international community of railway noise and vibration experts and to share knowledge as well as experience. Because an efficient transportation network is indispensable to handle the general mobility increase and road networks have reached their socio-ecological limits, the railway network is to be strengthened. For example the European Commission has given distinct political signals to get more passengers onto the railways. This policy represents a clear challenge for the next few decades not only for European railway companies: the considerable increase in mobility will lead to a doubling of the railway traffic volume within the next 10 to 20 years. To reduce the environmental impact, the Directive on the Assessment and M- agement of Environmental Noise has been put into force in Europe, aiming at avo- ing, preventing or reducing harmful effects of environmental noise on human health.
