ABSTRACT
Finding methods to provide a quiet passenger compartment in a car are highly sought after by automobile manufacturers. The ability to reduce noise inside the vehicle enhances the perceived value of the vehicle to the consumer, and so, a competitive advantage to the manufacturer. Several methods to reduce noise and its sources are employed, one of which reduces noise in the passenger compartment using sound absorbing materials attached to various components such as doors, quarter panels, trunk sides and floors, headliners, and others. This study attempts to quantify the ability of several cellulosic - based nonwovens to act as efficient absorbers, reducing the overall sound level in the passenger compartment by using ASTM C-384 "Impedance and Absorption of Acoustic Materials by the Impedance Tube Method". The results of testing will demonstrate that each of the cellulosic - based nonwoven composites contribute to the absorptive properties of the components, and are effective for overall noise reduction in the vehicle. The individual acoustic characteristics of the various vehicles would determine the type and amount of material required to provide the best results.
|