Item

Abstract

The binaural synthesis of acoustical environments is based on binaural room impulse responses (BRIRs) measured with a dummy head for discrete head positions and angular resolutions of typically between 1°and 15°. The resolution of the BRIR grid defines the size of the BRIR database as well as the duration of its measurement. To determine the minimum grid resolution required for dynamic binaural synthesis a listening test was performed. Following an adaptive 3AFC procedure, a spatial grid of BRIR data was gradually coarsened from a maximum resolution of 1° / 1° until audible artefacts were introduced. Thresholds of audibility were tested for a sound source located at 0° / 0° with dynamical auralization in two rotational degrees of freedom. The datasets used were acquired in an anechoic environment and in two rooms of different size and reverberation time. Pink noise and acoustical guitar were used as stimuli. A third octave band filter bank analysis of the data sets, using a 1dB-deviation-in-a-band criterion for the audibility of spectral differences, was in good accordance with the listening test results.