The purposes of this study were to investigate the effects of different road surfaces on vehicle interior noise and to investigate a method of predicting road noise from multiple surfaces based on noise measurements of a single surface. The primary focus is on coarse road surfaces. However, both smooth asphalt and rough road surfaces are included in the study.
A road surface survey was conducted to determine the effect of different road surfaces on vehicle interior noise. Weighting functions were developed for the purpose of modifying the noise response from one road to match the response of other roads. The weighting functions were experimentally derived from road noise measurements of a number of vehicles driven over different surfaces. A second group of vehicles were then tested to determine if road noise due to different road surfaces could be predicted accurately based on a single surface noise measurement.
It is concluded that road surface weighting functions (RSWFs) are a useful tool for estimating the vehicle interior noise due to different surfaces and investigating differences in road surfaces and vehicle nonlinearity. The potential applications of the RSWFs include both laboratory chassis rolls and computer model simulations. The implications to computer simulations are that similar RSWFs may be used to predict the noise response from a control road profile.