The challenge and solutions to providing consistent masking sound levels in individual rooms

Abstract

The propagation of sound in the built environment—impacted by size and geometry of a space, finishings, furnishings, and fit-outs—is exceptionally complex. It is for this reason that experts in acoustics need to consider all features of all spaces, despite the availability of prescriptive tools—e.g., categorization, acceptable-level and reverberation time [design] schemes—which are insufficient towards assuring any acoustical outcome. The use of a sound masking system is one acoustical solution that can be used to meet acoustical objectives, such as acoustical comfort and speech privacy, by reducing the variability in temporal, spectral, and spatial properties of sound within a space. The following investigation utilizes commissioning data of sound masking systems to underline the need for dedicated control zones for individual rooms. More specifically, the overall and one-third octave band levels of masking sound in rooms within the same control zone are compared against the project’s specifications (i.e., the target overall level and the reference masking spectrum). These results enforce opportunities to improve the performance of a sound masking system to realize more consistent perceptual (i.e., acoustical comfort and speech privacy) outcome.