Design of microperforated panels for broadband noise absorption inside vehicles

Noise inside vehicles decreases the passengers comfort. Most vehicles use lining materials to absorb this noise. Since the volume cabin is rather reduced, these liners must be light and thin, thus absorbing just in the high frequency range of the noise spectrum. Microperforated Panels (MPPs) provide a tool to develop thinner absorbers at lower frequencies. The utility of MPPs as wideband absorbers has been already proved. In this paper we discuss the design of even thinner MPPs capable of affording absorption inside vehicles in the frequency range of the cabin noise. A model is proposed which allows predicting the performance of such MPPs.