Review of the perception of diffusive surfaces in architectural spaces

Abstract

The use of sound diffusors started in antiquity in the form of statuary, balustrades, coffered ceilings, and surface ornamentation. While these surfaces added both beauty and useful scattering, their bandwidth was limited. It was not until the invention of the reflection phase grating by Manfred Schroeder in 1973 that acousticians were able to design number theoretic surfaces with a specified broad bandwidth. Later Cox and D’Antonio expanded diffusive design options beyond number theoretic surfaces to include fractal surfaces, binary amplitude diffusors and beautiful curvilinear architectural shapes acceptable to the architectural community, using shape optimization software. Many peer review publications and books by the authors, ushered in the widespread use of sound diffusion to complement sound absorption. Significant research ensued to study various shapes, bandwidth, location, coverage, and their perceptual aspects. This presentation will review how sound diffusion modified the sound fields originally in recording control rooms, followed by home theaters, rehearsal spaces, performance stages and auditoria, worship spaces, and sound reproduction spaces. Many applications will be presented, as well as subjective questionnaires and objective measures.