Effects of partial masking for vehicle sounds

In psychoacoustic assessments of vehicle sounds, the target sounds are usually presented in a quiet background. However, in practical applications, vehicle sounds are commonly superimposed by background noises. Therefore, in a pilot study, idle noises of two passenger cars with gasoline vs. Diesel engine were partially masked by a synthetic vs. a natural background noise. As synthetic background noise, uniform exciting noise (UEN) was chosen in order to compare the results to classic data from Zwicker for partial masking of pure tones by UEN. As natural background noise, a recording of a pedestrian area was used. The results are discussed in view of differences for different engines as well as background noises.