People know if they like the smell or not. Hedonic Tone Hedonics is the science of comparisons. Odor panelists compare an unknown sample to a set of known odorants. The panel decides which of the known odorants best describe the odor. The odor is assigned a rating, called the hedonic tone, based on the comparisons.
Hedonic tone provides a sense of the relative pleasantness of a sample.
Pleasant odors have positive hedonic tones, and negative hedonic tones indicate unpleasant odors. Table 2 lists hedonic tones for common agricultural odors as well as some of the odorants listed in Table 1. Hedonic Tone of Common Agricultural Odors. Odor Intensity Offensiveness tells us how bad an odor smells, and concentration gives us an idea how many molecules of odorants are floating in the air, but neither measure tells how strong an odor smells. For that, we need a third measure - odor intensity.