Odor intensity and pleasantness for a diverse set of odorants

Abstract

Data Analysis Office, U.S. Army Natick Laboratories, Natick, Massachusetts 01760 Observers compared the odor of butanol to the odors of various concentrations of 32 chemicals, and also rated the odor pleasantness and unpleasantness of these 32 odorants by a line matching procedure. All stimuli were presented to the observers by air dilution olfactometers. Odor intensity matches between each odorant and butanol were often describable by power functions. A derived magnitude estimate of odor intensity was obtained through a calibration of the butanol concentration scale. Most odorants grew less rapidly in intensity than butanol, and all odorants grew in intensity as decelerating functions of concentration. A more general function of the form P =: k 1 + k 2C k3 was needed to account for the pleasantness-unpleasantness judgments. In this study, most odorants were rated either neutral or unpleasant. Observers showed far more variability in hedonic judgments than in intensity judgments. © 1976 Psychonomic Society, Inc.