This paper describes a versatile software toolbox, which has been developed for researching, teaching and developing in the field of multichannel sound signal processing. The software system runs on a PC and consists on 5 modules covering the main stages and aspects of multichannel sound reproduction using loudspeakers. A number of new and efficient algorithms have been specially implemented for this software.

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This papers deals with a 3-D audio system that has been developed for desktop multimedia environments. The system has the ability to place virtual sources at arbitrary azimuths and elevations around the listener’s head based on HRTF binaural synthesis. A listener seated in front of a computer and two loudspeakers placed at each side of the monitor have been considered. Transaural reproduction using loudspeakers has been used for rendering the sound field to listener ears. Furthermore the system can cope with slight movements of the listener head. Head position is monitored by means of a simple computer vision algorithm. Four head position coordinates (x,y,z,φ) in order to allow free movements of the listener are continuously estimated. Cross-talk cancellation filters and virtual sources locations are updated depending on these head coordinates.

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In sound rendering systems using loudspeakers, the listening room adds echoes not considered by the reproduction system, thus deteriorating the rendered audio signal. Specifically, Wave Field Synthesis is a 3D audio reproduction system, which allows synthesizing a realistic sound field in a wide area by using arrays of loudspeakers. This paper proposes a room compensation approach based on a multichannel inverse filter bank calculated to compensate the room effects at selected points within the listening area. Time domain and frequency domain algorithms are proposed to accurately compute the bank of inverse filters. A comparative study between these algorithms by means of laboratory experiments is presented.

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