Synthesis and sound quality evaluation of exterior and interior aircraft noise

This paper discusses a noise synthesis methodology that is used to analyze the sound perception characteristics of interior and exterior aircraft noise. The synthesis approach is based on a decomposition of measured or calculated aircraft noise responses in design-relevant components. For exterior noise, these can be the broadband and individual tonal contributions from engines and airframe, for interior noise, these are the contributions from different sources and noise paths. The noise synthesis approach can be applied in making a quick assessment of the perception impact of individual contributing noise components. But one of the most relevant applications is in re-synthesizing target sounds that match the listener requirements and that can be translated in physical design targets for the various aircraft subsystems. The methodology is illustrated for the case of a flyover noise of an aircraft near an airport and for the interior noise in a jet and a propeller aircraft. The noise synthesis was extensively validated with a number of jury tests and by calculation of sound quality metrics.