Auraltypical acoustics? A critical review of acoustical foundations, standards and practices

The evolving concept of aural diversity was born out of awareness that there is a deeply embedded and intertwined, singular model of hearing at the core of the preponderance of acoustic standards and guidance, and hence practice. This is exemplified with the prescription of the ‘otologically normal’ hearer derived equal loudness contours (ISO 226:2003), giving form to ubiquitous A-weighted decibel – the ‘otologically normal’ characterising the hearing of healthy 18 to 25-year-olds. The consequence is the design and support of less favourable, even hostile acoustic environments for those that fall outside of this group, which can result in discomfort, distress, negative impact on health and well-being and societal exclusion. In order to understand the different aspects that underpin this ‘auraltypical’ situation, this paper critically reviews the prevailing set of acoustic standards and scientific methodology with reference to a case study on ultra-rapid hand dryers.