Composing with Cross-modal Correspondences: Music and Odors in Concert

We report two experiments designed to investigate cross-modal correspondences between a range of seven olfactory stimuli and both the pitch and instrument class of sounds as well as the angularity of visually presented shapes. The results revealed that odors were preferentially matched to musical features: For example, the odors of candied orange and iris flower were matched to significantly higher pitches than the odors of musk and roasted coffee. Meanwhile, the odor of crème brûlée was associated with a more rounded shape than the musk odor. Moreover, by simultaneously testing cross-modal correspondences between olfactory stimuli and matches in two other modalities, we were able to compare the ratings associated with each correspondence. Stimuli judged as happier, more pleasant, and sweeter tended to be associated to both higher pitch and a more rounded shape, whereas other ratings seemed to be more specifically correlated with the choice of either pitch or shape. Odors rated as more arousing tended to be associated with the angular shape, but not with a particular pitch; odors judged as brighter were associated with higher pitch and, to a lesser extent, rounder shapes. In a follow-up experiment, we investigated whether people could match specific pieces of music (composed to represent odors) to three of the odors (candied orange, crème brûlée, and ginger cookies). In one case (candied orange), a majority of the participants matched the odor to the intended piece of music. In another case (ginger cookies), another piece of music (than the one intended) was preferred. Finally, in the third case (crème brûlée), people showed no preference in matching the odor to the pieces of music. Both theoretical and practical implications of these results are discussed.