Global competition has drastically changed the NVH engineering process in aircraft industry over the last 20 years. The demand to consistently shorten and improve the development cycle has forced engineers to develop new methods to reduce needs for physical prototype testing and to increase prediction capability. Today, experimental, numerical and hybrid NVH modeling techniques are applied successfully in aircraft development, but still missing is the sound quality aspect or the human factor in this whole engineering process. It is of major importance that the verification of aircraft designs takes into account the subjective perception of the system characteristics.
To bring the sound quality aspect in the aircraft development process, a real-time Virtual Aircraft Sound (VAS) synthesis environment was developed. VAS can be considered as an innovative technology, allowing acoustical engineers to do a "virtual walk" through the aircraft cabin and assess the passenger perception at different positions. The interior noise synthesis within VAS is based on a compact model consisting of tonal components and third octave bands for the background noise.
Two interesting test cases were set up in which the model identification and sound synthesis approach were applied to a propeller plane and a jet engine aircraft. The interior noise synthesis was extensively validated with a number of listening tests and by calculation of sound quality metrics. The differences between synthesized and measured sounds were found to be very small for most positions in the aircraft cabin.
