Challenge B: An environmentely friendly railway Sound design studios for setting noise requirements on new rolling stock- a future scenario S. Leth, A Frid, A Mirza Bombardier Transportation, CoC Acoustics Specialist Engineering Östra Ringvägen 2 , 721 73, Västerås, Sweden email:
[email protected] 1 Abstract The target for railway rolling stock industry is and will be to provide vehicles that cause minimal annoyance to wayside residents and provide a pleasant and comfortable environment for the passengers on board, i.e. the keyword is sound quality. In a future scenario outlined in this paper customer requirements will not be formulated in the traditional way based on legislation and noise values on historical rolling stock. Instead customer and manufacturer are sitting together in sound design studios to define the customer requirements after listening to the sound of different design options. We have in this future situation thus moved away from the blunt and one-dimensional dB(A) level and are looking at how to achieve an attractive blend of different noise sources and to adjust their characteristics. This can be done without having to resort to the various complicated sound quality metrics that exist today. In spite of their complexity, the metrics risk to be very limited in comparison with the full multidimensional sound experience in the human brain. With the use of sound synthesis tools it will be possible to auralise different design options in the sound studio and let the human ear and brain decide. Furthermore, aspects like privacy and conversation intelligibility between neighbor passengers could also be demonstrated and fine tuned in the sound studio.