Cost-benefit analysis (CBA) is a useful method to support decisions on rail noise mitigation. The applicability of CBA was investigated for five fields of application: pass-by noise (legal requirements and perception), depot noise, ground vibration, and interior noise/acoustic comfort. The method was demonstrated to work well for assessing the cost-efficiency of different mitigation measures for pass by noise and legal requirements. An innovative, perception-based approach (soundscape approach) that uses passengers to rate the acoustics was tested successfully for assessment of interior acoustic comfort.
Operational transfer path analysis (OTPA) was used to identify and rank main railway noise sources for the TramLink prototype of Stadler Rail Valencia. These were measured for real operation conditions on the Valencia network. Based on these measurements a model was built with the capability to predict design changes. To validate the model, a second measurement campaign was carried out in Gmunden on a TramLink. It was shown that the model is capable to predict certain design changes for trains of the same family. As OTPA works in the time domain, the data could be used directly for auralisation.
Within the project, different experimental source characterisation methods were investigated when applied at train-level in real-life conditions. It was found that in-situ structure-borne sound source characterisation is a useful method for application in the railway industry.
The first A&V (auralisation and visualisation) model for railway noise based purely on physical processes was developed. Four different output modes are supported by the A&V system: classroom presentation, spatial video and audio for web-sharing platforms, presentation in a studio with loudspeaker array and rendering for virtual reality with a head-mounted display. Several demonstration scenarios were developed for freight and regional trains. The model allows varying different parameters like rail and wheel roughness in a controlled way. Listening tests can be carried out to research the effect of mitigation options before implementing them. Interior railway noise A&V was investigated using binaural replay of spatially placed sound sources. Visualisation of the train interior was achieved by a combination of 3D modelling of the train structure and passengers and videos of the moving landscape. The applicability was demonstrated through a listening test (speech intelligibility) in virtual reality using a head-mounted display. The complementary project FINE 1 supported this task by delivering valuable input data for both auralisation and visualisation.
An analysis of the technical feasibility of selected new technologies to improve sound insulation of windows was carried out. Applicability and benefits were discussed.
All public results and further information can be found on the project website. A&V demonstration videos were put on YouTube so that everyone can experience the project outcome at home: www.youtube.com/playlist?list=PLFHEzMwLXvjGY4KUMNR1PWGPWXj40jXnk. Project results were presented at several scientific conferences (e.g. Internoise 2017, Euronoise 2018 and ICSV 2018) and in articles and conference papers. A&V scenarios were demonstrated at Innotrans 2018 at the Shift2Rail stand. The project results will mainly be exploited in PhD theses and future research at universities, for improved services of consultancies and improved acoustic design of trains. The A&V demonstrator will be used as:
1. A communication tool, which is made available to public authorities for information purposes,
2. A research tool to provide audio samples for psychoacoustic listening test to explore the effectiveness of noise mitigation measures from a subjective point of view and
3. A service for rail vehicle manufacturers and infrastructure operators to support noise related issues.
