Abstract:
This paper deals with the acoustic optimisation potential of a type of noise which is not sufficiently described in acoustic literature. During the starting phase of modern railbound vehicles, apart from other sources such as the gear coupling, the traction motor is a dominant sound source. A study concerning sound generation, perception and optimisation has been carried out. In this paper, aspects of sound generation and results of listening tests are summarised, whereas the role of consonance and roughness is described in detail. First, a rating-scale test with stimuli from real recordings yields no significant influence of roughness on pleasantness. But afterwards, a sound-synthesis model is introduced and validated which is able to reproduce sounds inside railbound vehicles. With this model, a variation of the gear teeth number verifies that pleasantness is very probably dependent on the consonance effect. Instrumental roughness models, however, do not reproduce the sensation of consonance completely.