Virtual sound modeling and real-time rendering in aircraft simulator

Virtual sound modeling and rendering are key technologies in the virtual environment of an aircraft simulator. Based on physical acoustics, psychoacoustics, architectural acoustics, room acoustics and digital audio technology, a synthetic underline audio modeling method and an optimal dynamic audio rendering algorithm are presented for a distributed aircraft simulation system. Large-scale sound data are remodeled by the digital compressor, expander and aural exciter. A 5-segment equal loudness level contour is proposed and an advanced compressor ratio algorithm is realized based on psychoacoustic parameters. An equivalent absorption coefficient and reverberation time estimating algorithm are also presented based on virtual capsule environment information. Frequency spectrum and formant data samples are summarized according to different state variables and a back propagation (BP) network algorithm is realized by several equalizer parameters adjusted in real-time thrust noise simulation. A real-time virtual sound system is adopted in a certain aircraft simulator based on high level architecture (HLA) which makes the aural rendering more accurate and vivid.