Rating criteria for vehicle in-cabin noise with emphasis on HVAC system operation

Noise and vibration have an important influence on a customer's perception of vehicle quality. It is the purpose of this study to introduce a standard test procedure for measuring vehicle in-cabin noise levels. A combined vehicle base noise with all possible sources, including HVAC system, tyres, aerodynamics, under various driving conditions, is considered for developing the total vehicle cabin noise rating criteria. Results from 21 different vehicles were analysed and used to determine a star rating for the vehicle industry, which incorporates loudness, communication and annoyance of the measured data. Using sensitivity analysis, weighting is given to those parameters having prominent impact on the in-cabin noise levels, to arrive at a combined factor, which then is translated into a star rating.