The aromas in the universe can be termed as infinite; it is only now that one can understand the odors which human olfactory mechanism could detect. A recent study has pegged the figure at 1 trillion which is almost a hundred million times over the general consensus on the ability of detecting odors by humans.
The study involved gauging the ability of human nose to detect different odors and the results showed that the human nose is far more sensitive than what it is normally credited for. Medical science is well accustomed to the limits of human auditory and the visual sense organs. This experiment for the first time tried to benchmark the abilities of the human nose. The nose happens to be the most sensitive sense organ when compared to the abilities of the other sense organs. The eyes for example can differentiate between a few million colors while the ear can hear some 340,000 tones. The nose on the other hand can differentiate a trillion different odors.
Study author and molecular neurobiologist Leslie Vosshall of the Rockefeller University said, “Ten thousand is kind of pathetic — it’s a pretty low number. It led to the idea that humans have a comparatively low sense of smell.”
Using a procedure much akin to a hearing exam in which participants have to distinguish between two tones, Leslie and her colleagues put 26 noses in the test. Every subject was given 3 vials, two of them having the same odor. Participants were told to identify the odd one out. Each subject was made to go through hundreds of these tests and the assumption was made that subjects’ performances would be similar in recognizing all possible smells able to be made in the lab. The researchers inferred that an average human nose can distinguish over 1 trillion odors.
The earlier figure of 10,000 odor estimate was based on an earlier outdated manuscript by two American chemists who based their scent classification on four distinct odors- fragrant, acid, burnt and caprylic. It was much akin to the primary colors which made up all the colors. The latest work confirms that odor is an incredibly rich, variable, and nuanced medium.
The study was published online Thursday in Science.