Sound source modelling by nonnegative matrix factorization for virtual reality applications

Auralization is a suitable method for subjective noise evaluation of virtual prototypes. A basic requirement is the accurate modelling of the sound sources. This includes a dynamic and parametric description at multiple operating conditions. In the case of wave propagation including flow, such as aircraft or vehicle noise, aeroacoustics or fluid dynamics simulations are practically limited to the acoustic near field due to high computational costs. Especially challenging are simulations of rotating systems, such as fan noise radiation. For better applicability, the proposed method is based on in-situ recordings of flyovers. The processing chain compensates for source position and movement as well as atmospheric and soil damping effects on recorded data. The compensated source signal is decomposed into partial sources in spectro-temporal domain with nonnegative matrix factorization (NMF) and can optionally be enhanced by physically-based source information. The format of the source model obtained is ready to use for dynamic sound synthesis in real-time virtual reality applications.