Perception of non-stationary wind noise in vehicles

Abstract

Predictors of people's responses to noise inside cars are used by car companies to identify and address potential noise problems. Because significant advances have been made in the reduction of engine, powertrain, and tire/road noise, it is now important to pursue reductions in wind or aerodynamic noise. While models of loudness are commonly used to predict people's responses to stationary wind noise, some wind noises are less acceptable than is predicted by the loudness metric. Additional sound characteristics may account for this. Two listening studies were designed to examine the usefulness of including sound quality metrics in addition to loudness and sharpness in models used to predict acceptability for non-stationary wind-noise sounds, particularly noise with the kind of variations that are expected from wind gusts. Test sounds were based on recordings made in cars in a wind tunnel. A simulation method was implemented to generate sounds with controlled gusting features by modifying stationary noise recordings. A gusting metric was designed to predict subjects' acceptability responses based on the strength, modulation rate, and duration of the gusts.