Individual road vehicles have to satisfy severe noise emission limits on European and other markets. For an optimal design towards low noise emission, there is an interest in quantification of contributions of the sources on the vehicle and more specific of components of the engine. Airborne Source Quantification is the name for a source-transfer function approach to diagnose airborne noise emission. Source strengths and pressure contributions have been identified on a large truck. The analysis can be used to verify the effectiveness of the encapsulation and give targets for engine component development. The main steps in this process and results will be discussed.
