There’s a car coming? - Psychometric function for car pass-by in background noise based on simulated data
Regular paper
Chalmers Technical University
Wednesday 3 june, 2015, 11:20 - 11:40
0.7 Lisbon (47)
Abstract:
To be able to define what parameters that determine the perception of an approaching car in background
noise is an important issue in traffic safety. The more silent cars become the more important it is to
understand the determinants that makes people recognize an approaching car.
Most studies on cars in background noise are based on real recorded situations. This requires that
suitable recordings have to be made both for the background sound as well as the test sound. This is a
requirement that both limit the control of the situation as well as the degrees of freedom.
In the presented study another approach has been employed. The sounds are based on an auralization
method that enables car sounds to be simulated based on the tyre and road interaction and desired
engine sound. The sounds can be generated for any desired speed and distance. Single car events can
thus be superposed to background sound with full control of all parameters. This allows evaluating the
psychometric functions for single parameters. Using this setup enables a deeper understanding of the
perceptual space for a car in background noise. The used auralization method has in earlier studies been
validated for giving good perceptual ratings compared to recorded sounds.
The present study measured both the reaction time and the recognition of cars passing by in the
foreground with a busy street in the background. In this study the distance of the background street is
varied and all other parameters are kept constant. To be able to determine how the recognition of the
foreground car is varied dependent of distance to the background street the same car-type was used in
both back and fore ground.