Abstract
Various sources of noise in diesel- engine commercial vehicles are discussed, thereby describing the methods of noise reduction by the application of high transmission-loss enclosures and paneldamping materials. Examples are given of this practical application of acoustical treatment in order to reduce the noise within the car. It is demonstrated that useful reductions can be achieved by palliative treatments, but attention is drawn to the practical and economic difficulties associated with the incorporation of this sound reducing treatment in production vehicles.