Advanced Microphone Array Technology for Enhanced Sound Source Localisation in Cabins

Abstract

Cabin noise generation is an important issue to accompany the weight saving strategies for pollutant emission reduction. The turbulent boundary layer forces vibrations on the fuselage which are transmitted and radiated into the cabin by the lining, the floor and the windows. In addition the engine and system noise like the hydraulic system and the air conditioning unit contribute to the cabin sound field. To improve the noise-depending comfort in cabins the contribution of each the sound radiating lining and/or the air conditioning have to be distinguished. The sound intensity measurement technique can be applied in this difficult environment (reverberant sound field) to measure the energy contribution of the lining. Nevertheless, this method is very time-consuming. Therefore, the department of Experimental Methods at the German Aerospace Center (DLR) Göttingen developed a new microphone array for in-flight applications.