Scientists in the US believe they may have calculated a mathematical formula to create an olfactory form of 'white noise' that could cancel out the smell of bad odours.
Kush and Lav Varshney, brothers who work at the IBM Thomas J. Watson Research Center in New York, have created a database to measure how humans perceive certain smells based on their physical and chemical properties.
Their database gives each odour a rating so, as New Scientist notes, one compound could rate something like 5.6 chalky, -3.2 celery and 0.8 cedar wood.
To cancel out a smell they try to find the exact opposite of those compounds and their research has shown that the combination of around 30 of them could create the perfect white noise or, in this case, white smell.
White noise is created by is a spread of different sound frequencies of equal power and white light by all the different visible wavelengths at the same intensity, but as yet no one has quite been able to produce an olfactory equivalent.
The brothers haven't quite created an odour-cancelling device yet, but are confident their calculations will check out and hope it could be used to improve air quality in public buidlings, on transport systems and even to transform the smell of certain food types that picky eaters find offensive.