Spatial Audio

Spatial Audio

Apart from surround capture and synthesis of acoustic scenes, research is undertaken regarding the sound radiation of individual sound sources, e.g. musical instruments, in order to capture and reproduce them in their entirety. In reproducing acoustic images, methods involving both loudspeakers and binaural methods are implemented.

Spatial Audio

The long-term focus of the topic of spatial audio for recording and production is on (higher order) ambisonics technology. By way of a series of concerts in the IEM-CUBE, MUMUTH and short-term installations for spatial live electronics in contemporary concerts, research is aimed at constantly adapting this technology to the quality demands of artistic implementation. New methods of decoding, spatial signal improvement and recording of ambisonics as well as perceptual evaluation are also in the focus of research activities.

Research at the IEM also deals with binaural applications requiring merely a pair of headphone signals for both ears in the production of virtual acoustic reality. For these methods, on the one hand, research is being undertaken into the data-based modelling of existing acoustic spaces, and on the other hand, current research activities involve a variety of algorithms for the artistic production of acoustic realities.

A further active research area is in the adaptive improvement of sound recordings using microphone arrangements in acoustically adverse situations.  Here, both modal as well as purely adaptive methods are investigated for accommodating acoustic directional sensitivity, and these are in particular aimed at speech in the context of small microphone arrangements. To supplement this, beam-forming methods are applied which can be used in the reproduction of virtual acoustic reality without headphones.

Sound sources with direction-dependent sound radiation are also investigated using the spherical sound field descriptions of ambisonics technology. For this, compact spherical loudspeaker arrangements for the direction-dependent reconstruction of sound sources or for artistic radiation synthesis are investigated. This method strives to extend virtual acoustic reality and spatial acoustics. Research is also aimed at continually adapting technology to the quality demands of artistic implementation and in developing new, efficient algorithms

The directional dependence of musical instruments is investigated using a spherical microphone arrangement, which allows produced sounds to be mapped simultaneously to a variety of surround directions. The composition of sounds can be exactly determined for different directions of propagation using spherical separation methods. In this way, the timbre or the spectral composition for different directions can be systematically investigated. Apart from holographic transmissions of solo instruments in concert halls, new algorithms are being investigated which involve a simplification of the recorded information without causing a  deterioration of the sound. The sound radiation can be restored either by means of spherical loudspeaker arrangements or in terms of virtual acoustics.

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