Zampini & Spence (2005) clarified that the perception of crispness and staleness of potato chips was affected by modifying the biting sound. This result shows the possibility of improving the taste of the food by auditory stimuli. In this study, we conducted an experiment using nursing care food. Nursing care food is soft and easy to eat for people who have difficulty in chewing and swallowing, but it has less crispness and we don't feel it tasty. So in this study we discuss the possibility of improving crispness, staleness and the taste of nursing care food by using sound.
In the experiment, twelve subjects asked to eat nursing care food (real formed chicken cutlet) with three sound conditions; no sound, hearing biting sound and hearing music. After each eating session, they rated crispness, staleness and the taste of the food by five points bipolar scale. They also rated six onomatopoeic scales; Petopeto, Saku-saku, Karikari, Gunya-gunya, Pari-pari and Mochi-mochi by five points scale from "I don't think so" to "I think so".
Subjects wore earplugs during the experiment and the biting sound or music was presented them by bone conduction headphone. Biting sound was recorded by bone conduction microphone in advance, which was recorded when one of experimenter ate real cutlet. Music was a free piano music, selected from website (OtoLogic: https://otologic.jp).
The result of cluster analysis on the ratings of no sound condition showed that subjects were classified into 3 clusters. Although the result of one-way ANOVA on crispness for cluster 1 (n=9) showed that the main effect of sound was not significant, subjects rated that biting sound condition and music condition were rated crispier than no sound conditions. This result shows the possibility that the auditory stimuli affected crispness of nursing care food.