The International Institute of Acoustics and Vibration (IIAV) and The Institute of Acoustics (IOA)
Abstract
With its inclusion of “hearing impairments and hearing aids” as factors that may “influence auditory sensation”, within the criteria of the new International Standard definition and conceptual framework of soundscape (BS ISO 12913-1:2014), we witness a sea change in how a standard in acoustics may regard hearing: not as a fixed, universal and generalizable metric predicated on the otologically normal (BS ISO 226:2003), but as a shifting, unsteady human trait that we individually, tacitly know from day to day experience. This paper will present a case study that exemplifies the pressing need for such as sea change. It will present the issues arising from a preliminary study of the noise effects of ultra-rapid “ecological” hand dryers in publicly accessible toilets. They are very popular due to impressive data and marketing on efficiency, effectiveness, hygiene and speed, the adverse corollary is a dramatic increase in sound pressure levels in this socially sensitive environment. The study comprised of sound power tests, followed up by in situ sound pressure tests in a range of different sized WCs. The most extreme example from this study showed one dryer in a reverberant public toilet had the equivalent combined Leq of 19 dryers in a free field environment. From provisional interviews it appears that the noise effects are impacting on a wide range of vulnerable subgroups: breast-feeding mothers, infants and children, dementia sufferers, the visually impaired, hearing aid users and most seriously the discomfort on those with hyperacusis and hyperacute hearing in ASD. This study functions as a microcosm for soundscape/environmental noise issues in the urban environment. The paper will conclude with a proposed paradigm for situating hearing in acoustics that extends from a normative, clinical model of hearing, the otologically normal to a socio-cultural concept of the auraltypical and auraldiversty
