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To solve interior rolling noise issues after vehicle development has been finalized, a robust procedure is desired, which combines the strengths of both the experimental and the simulation world. This paper proposes a methodology that is focused on rolling noise issues in the frequency range from 100 to 600Hz and whose core is constituted by a source identification procedure. By means of an inverse method that makes use of the information coming from several microphones, each of the interior areas of the passenger compartment walls is identified as an equivalent source and one can then determine which one is the most contributing to the interior noise under operating condition. This allows a direct and optimized application of countermeasures aimed at the reduction of the interior rolling noise.

In the acoustic study of the interior noise of a vehicle, whether for structure-borne or air-borne excitations, knowing which areas contribute the most to interior noise and therefore should be treated as a priority, is the main goal of the engineer in charge of the NVH. Very often these areas are numerous, located in different regions of the vehicle and contribute at different frequencies to the overall sound pressure level. This has led to the development of several “Panel Contribution Analysis” (PCA) experimental techniques. For example, a well-known technique is the masking technique, which consists of applying a “maximum package” (i.e., a package with very high sound insulation) to the panels outside of the area whose contribution has to be measured. This technique is pragmatic but rather cumbersome to implement. In addition, it significantly modifies the dynamics and internal acoustics of the vehicle.