Noise transformation: A critical listening-based methodology for the design of motorway soundscapes

The purpose of this paper is to report the results of an industry-funded qualitative interdisciplinary research project that has produced a new approach to motorway noise management called “noise transformation”.

Four iterative design tests guided by listening as methodology. These included field recordings, laboratory tests and two field tests. Field tests were conducted in combination with ethnographers, who verified community responses to field-based transformations.

Transformation requires an audible perception of both background and introduced sounds in all instances. Transformation creates a 1–2 dB increase in background sound levels, making it counterintuitive to traditional noise attenuation approaches. Noise transformation is an electroacoustic soundscape design method that treats noise as a “design material”. When listening to motorway noise transformations, participants were actually experiencing another rendering of a sound that they had already acquired a degree of attunement to. Thus, they experienced transformations as somehow familiar or normal and easy to feel comfortable with.

Noise transformation is a new approach to noise management. Typically, noise management focusses on reduction in dB levels. Noise transformation focusses on changing the perceptual impact of noise to make it less annoying. It brings together urban design, composition and ethnography as a means to think about the future design of outdoor environments affected by motorway traffic noise, and should be of interests to planners, designers and artists. The authors have structured the paper around listening as methodology, through which both design and ethnography outcomes were achieved.