Glazing for Vehicle Interior Noise Reduction

As noise levels within vehicle cabins continue to be reduced, wind noise and traffic noise transmitted through the glazing increase in importance in the quest to achieve further reduction. With consumers ranking cabin noise as an important factor in vehicle purchase decisions, and with the projected increase in vehicle telematics, including speech recognition systems, the need for even quieter interiors will continue. NVH engineers have not recognized that vehicle glazing offers an effective option for noise reduction; often, only monolithic glass has been considered, where the only option for improvement has been to increase the mass (increasing the thickness and the vehicle weight). This paper presents sound pressure loss data for laminated glass compared to the tempered glass typically used for side, rear and roof glazing today. The sound pressure loss results show a significant opportunity for improvement in the 2000 to 6000 Hz region, a key range for human conversation and the key range for wind noise. Along with this acoustic improvement is a reduction in mass of the glazing.