Research areas Binaural Hearing / Acoustic Measuring Techniques / Acoustic Virtual Reality

In order to improve the quality of binaural based virtual reality systems, the use of individual head-related transfer functions (HRTF) plays a major role, specially for localizing elevated sources.



A system for individual HRTF measurements was constructed at the Institute of Technical Acoustics in Aachen. In this set-up the common far-field assumption of a plane wave incidence on the head is not assumed and thus great care was taken to design a loudspeaker which radiates as similar as possible to an ideal point source in a wide frequency band (300 Hz to 16 kHz).

The supporting arc is constructed with thin metal sticks in a trellis structure in order to minimize disturbing reflections till high frequencies. Up to 40 loudspeakers can be freely positioned, allowing a flexible choice of the employed measurement grid. Arm and neck supports are built to assist the person under measurement to stay at rest at the same position for the entire duration of the measurement, which takes less than seven minutes to complete. New measurement methods are being investigated to reduce the required measurement time even further.