Relationship between the nature of chewing sounds and the emotions generated, excluding the effects of taste, aroma and texture

Abstract

Chewing sounds are an important component contributing to the perceived "deliciousness" of food. This study clarified the tonal and emotional evaluations elicited solely by chewing sounds, excluding the influences of taste, aroma, and texture. The participants comprised 25 employees of a company affiliated with the first author. A total of 22 types of food, including frozen desserts and sweets, were evaluated by the SD method. Principal component analysis revealed that 83.7 % of the tonal evaluation variance was explained by the first principal component, which ranged from "hard/cracked" to "vague/weak". Similarly, 79.9 % of the emotional evaluation was explained by the first principal component, which ranged from "motivating/arousing" to "depressed/calm". A strong correlation was observed between the scores of the first principal component and the tonal and emotional evaluations (r=0.984). Cluster analysis grouped the chewing sounds into four clusters: high arousal, semi-arousal, semi- subsidence, and high subsidence. Metallic and hard sounds tended to evoke feelings of motivation and arousal, whereas weak and vague sounds were associated with depression and subsidence. Spectrogram analysis indicated that metallic and hard chewing sounds produced high sound pressure levels in high frequency bands over short durations, while weak sounds produced low sound pressure levels in low frequency bands over longer periods. These findings suggest that differences in food structure affect both the tonal and emotional perceptions of chewing sounds.