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, which is similar to pink noise, but has the additional advantage that it shows the same level in each critical band. As natural background noise, a recording of a pedestrian area was used. The results reveal different partial masking for different engines as well as background noises. Effects of sound signature seem to play an important role in partial masking of real world sounds.