抄録
In a dental treatment, doctors and patients often feel strong discomfort feeling by hearing the dental treatment sound. It is caused by spectral peaks in a higher frequency. For reducing discomfort feeling of spectral peaks, we have previously proposed the discomfort reduction method that can mask spectral peaks on basis of auditory masking by emitting the masking signal. In principle, this method has a problem that it requires emission of the masking signal with higher power. It may inflict discomfort feeling on listeners. On the other hand, we focus on chords in music theory because they are generally known as typical comfortable sounds. The chords have the spectral structure that multiple spectral peaks are held with specific rules, and the temporal structure changes on basis of the chord progression of musical pieces. These suggest that we may design the comfortable sound by reforming the spectral structure of the dental treatment sound to that of chords. In this paper, we therefore propose the comfortable sound design method based on chord-forming of the spectral peak in time and frequency domains for the dental treatment sound. As a result of subjective evaluation experiments, we confirmed the effectiveness of the proposed method.