Novel modelling approaches to enhance sound quality
New methods are needed to better evaluate and model room acoustics. This is because scientists are not completely aware of the link between objective attributes and subjective measures with respect to room acoustics. To address this issue, the EU-funded PHDVIRTA (Physically-based virtual acoustics) project set out to find novel techniques to simulate and measure sound propagation in rooms, with a particular focus on music halls. Project partners examined authentic auralisation – the creation of a virtual auditory environment that is indistinguishable from a real one – in order to pursue novel and reliable modelling methods for room acoustics. An exploration of modelling for reflections from rough and scattering surfaces led to innovative geometric acoustics modelling methods. They conducted case studies by employing a wave-based modelling technique on the acoustics of ancient theatres, the seat-dip effect and sound reflection on layered wall structures. The consortium developed novel methods to record sound in a concert hall and to authentically reproduce the recordings with spatial sound reproduction in the lab. To better assess concert hall acoustics, the PHDVIRTA team invented a loudspeaker orchestra that simulates a symphony orchestra with 34 loudspeakers. It was able to record concert hall acoustics for the simultaneous comparison of different halls. The measurement system allows detailed analysis of spatial impulse responses, which is essential for understanding how sound propagates in a concert hall. Researchers extensively studied augmented reality audio technology, resulting in several new methods that use gestures to control the menu structures in mobile devices. They also looked into the technology's applications in relation to future personalised mobile audio communications. Thanks to PHDVIRTA, augmented reality audio applications are set to improve communication, while the acoustics research will lead to new quality metrics and the creation of authentic auralisation. Tomorrow's concert halls and public places such as libraries and shopping centres will sound better.
Keywords
Room acoustics, concert halls, PHDVIRTA, virtual acoustics, auralisation, augmented reality audio