The smell is dubbed “olfactory white,” because it is the nasal equivalent of white noise, researchers report today (Nov. 19) in the journal Proceedings of the National Academy of Sciences. Just as white noise is a mixture of many different sound frequencies and white light is a mixture of many different wavelengths, olfactory white is a mixture of many different smelly compounds.

In fact, the key to olfactory white is not the compounds themselves, researchers found, but the fact that there are a lot of them.