The concepts of white noise and white light are well understood in the fields of audiology and optics. New research has demonstrated that the human sense of smell also has a limit characterized as ‘a common perceptual hum’ and its called ‘olfactory white.’ By generating ‘multi-component mixtures,’ researchers determined that the resulting scent masks all other odors around it. A team led by Noam Sobel, a neuroscientist at the Weizmann Institute of Science in Rehovot, Israel, said ‘One might imagine that the more odors are added, the more “special” the odour would become. Yet what we show is the opposite.’
Sobel’s team experimented with aroma molecules from across the scent spectrum. Research volunteers reported that with each combination ‘the mixtures became more similar to each other, despite not having a single component in common.’ The trend indicates that at a certain point, human perception converges, unable to distinguish between mixtures.
A further experiment by Sobel and his team demonstrated potential for practical applications of olfactory white. The smell of rose is created by combining four key molecules. When combined with olfactory white, the scent of rose was rendered undetectable. Olfactory white could potentially be used to mask odors, from the smell of public toilets, cocaine, or explosives.
Photo: liveandrock, Creative Commons
Source: Corbyn, Z (2012) ‘The whiff of white’ Nature DOI: 10.1038/nature.2012.11846