The Nose Knows by Robin Koontz
How much does your nose know? Up until a few months ago, we were taught that humans have one of the worst senses of smell of any creature with a nose. While even a – can detect about – different scents, human noses were believed to only sense about 10,000 different smells. That accepted conclusion was based on a study done in the 1920s, and according to Leslie Vosshall, who recently co-authored a new report with Andreas Keller about human sense of smell, that study was not backed by data. She and Keller blew the nearly one hundred year old study to the moon with their data-based research which concluded that we humans could potentially detect as many as a TRILLION different smells!
In the earlier study, scientists assumed that people could only discern about ten different intensities in each of four odor “qualities,” which were either fragrant, acidic, capric (like sweat), or burnt. All of the options amounted to the 10,000 number (10x10x10x10). In the new study, the researchers combined 128 odor molecules from a wide range of smells into various, unique mixtures. The mixtures contained 10, 20 or 30 different components. And rather than employ professional sniffers for the testing, they found volunteers from the community to participate in the study.
The volunteers were given three vials at a time – two identical and one slightly different. Their job was to pick the smell that was different. As for the trillion smell theory, that’s all it is.