A Reciprocity Technique for Analysis of Sound Radiation from Vibrating Components of Vehicles : 2nd Report, Measurement of Contribution of Body Panels to Acoustic Transfer Functions

Abstract

One characteristic of a fully trimmed vehicle is that the properties of the acoustic field around the noise sources have approximately the same level of complexity as those of the acoustic field in the cabin. Another characteristic is that the partitions between the noise sources and the interior have double-wall structures consisting of interior trim and metal panels covered with damping materials. We present a method that combines direct and reciprocal measurements to determine the respective contributions of the metal panels and interior trim to the acoustic transfer functions between the noise source surfaces and the driver's ear position. We then explain how an analysis of the contribution of the metal panels to engine noise and transmission noise in a fully trimmed vehicle can be useful in achieving substantial noise reduction.