The visual preference and physiological response to Sierpinski triangle acoustic diffuser: An experimental study using VR technique

Abstract

Diffusive surfaces should be optimally designed for acoustic and aesthetic purposes. Fractals are commonly used to adapt to the parametric demands of interface design combining mathematical calculation and artistic creation. The author’s previous study proposed an improved fractal acoustic structure based on the Sierpinski-triangle building rule. However, there is insufficient research on quantifying the physiological and visual benefits of such fractal features. Focusing on fractal iteration and randomness of module arrangement as fractal parameters, this study investigates in 3D-virtual reality meeting rooms and identifies the influence of fractal diffusion structures on visual preferences and physiological responses. Variance analysis is used to construct models of fractal parameters, subjective preference factors, and physiological indicators. Results suggest that the Sierpinski-triangle pattern iterated twice with mid-high complexity (quantified by the fractal dimension D = 1.58) is significantly more visually preferred than other fractals. When the modules are at low randomness (quantified by P = 0.25), more random module arrangements elicited better beneficial outcomes. However, as the degree of randomness increased, effects became increasingly irregular. Subjective evaluation factors and physiological indicators show a strong correlation. To sum up, the use of the medium to mid-high complexity fractals in interior spaces would help enhance the visual preferences and stress relief of occupants.