Spatial sound reproduction for interactive hearing research

The use of sound field synthesis for hearing research has gained popularity due to the ability to auralize a wide range of sound scenes in a controlled and reproducible way. We are interested in reproducing acoustic environments for interactive hearing research, allowing participants to move freely over an extended area in the reproduced sound field. While the physically accurate sound field reproduction using sound field synthesis is limited to the sweet spot, it is unclear how different perceptual measures vary across the reproduction area and how suitable sound field synthesis is to evaluate them. To investigate the viability of listening experiments and provide a database for modelling approaches, simulations of binaural cues were carried out for the Simulated Open Field Environment loudspeaker array. Results show that the binaural cues are reproduced well close to the array's center, but exhibit more variance than in the corresponding free field case further to the sides. The binaural benefit in speech understanding is reproduced well in the center, with errors lower than 1 dB, but errors increase up to 6 dB close to the loudspeakers. We show that these deviations are driven by errors in better-ear signal-to-noise ratio and that the binaural unmasking contribution is reproduced faithfully.