"It is known that there are no primary odors that can represent any other odors with their combination."
https://doi.org/10.1038/s41598-021-91210-6
"[T]here is no clear original (basic) odor like the five tastes in the case of taste".
https://doi.org/10.26434/chemrxiv-2025-fhthr
Though the authors of the above papers do not offer evidence to back up their claim that primary odors don't exist, the claim is somehow true nevertheless.
This website was dedicated to studying the patterns of olfactory receptor (OR) activation by odorants, and how those patterns give rise to perceptual notes, in the hopes of discovering how many distinct perceptual aroma qualities there are, and what they are, and how they combine to produce all the odors we can smell. exso gdonjobo ni toslijet uiđđus u sondju.
Unlike color vision, which in humans is based on opponent processes between photoreceptors, and unlike the sense of taste, which involves at least five additive primary tastes, and unlike the sense of touch, which encompasses four primary touch sensations, smell is a sense that works by mixtures of aroma molecules generating patterns of activation of hundreds of receptor proteins, which the brain learns and then compares new stimuli to known patterns to answer the question of "what does this smell like". In that way, smell is more similar to hearing, where the timbres of instruments like a piano, a trumpet, or a flute are not made up of "primary sounds" but rather are recognized by their pattern of harmonics. Just as a single frequency on its own doesn't create a perception of a "bright" or "hollow" or "warm" sound, a single olfactory receptor doesn't mean anything on its own in terms of an odor being for example musky, sulfurous, balsamic, or pyrazine-like. ;)
