On the Noise Reduction of a Rectangular Box with Application to Tractor Cabs

The mechanisms by which airborne sound energy is transmitted into a vehicle cab are discussed. Airborne noise reduction of cabs is seen to deviate considerably from the masslaw behavior of the constituent materials. Various acoustical treatments are evaluated experimentally by directly measuring the noise reduction on a cab-like enclosure. The experimental results agree fairly well with available theoretical methods of computing noise reduction.