A case study on the perceptual differences in finite-difference time-domain-simulated diffuser designs

摘要

This paper presents a method to determine if differences between the scattering created by geometrically-similar diffuser designs are perceivable. Although there exist standards to measure the scattering and diffusion coefficients, the perceptual evaluation of the scattering created by diffusing surfaces has previously been scarcely examined. In the context of the optimization of a diffuser design, such audibility study can be used to assess the relevance of optimized geometries from a perceptual point of view. The proposed approach uses finite-difference time-domain (FDTD) numerical simulations to generate impulse responses (IRs) from which diffuser responses of geometrically-close designs are extracted. For each diffuser geometry, a set of three such time-domain responses convolved with a click-like signal, white Gaussian noise, and a male speech, are used as stimuli in an ABX listening test. Percentage of correct answers show that subjects are able to perceive differences for the click stimulus for all tested conditions (geometries and receiver positions), while discrimination rates are mitigated across conditions for the white Gaussian noise, and are not significant for the speech signal. Results also indicate that subjects' performance depends on the receiver location.