Fig 1.
Participant answers to the question: “How much do you agree that each adjective is appropriate to express the impression of the sound of dental drills?”
Participants were asked to score their responses for each adjective on a 5-point scale ranging from “strongly agree” (level 1) to “disagree” (level 5).
Table 1.
List of dental drills used.
Fig 2.
Subjective impressions to the sounds of Drill E.
Fig 3.
Waveforms of Drill E under idling and drilling conditions.
Fig 4.
Spectrograms of Drill E sound.
A spectrogram is an image that incorporates frequency (y axis), time (x axis), and amplitude (brightness of color).
Table 2.
Physical properties of the sounds produced by 12 types of dental drills.
Table 3.
Results of factor analysis for the adjective pairs used to characterize dental drill sounds.
Table 4.
Correlation coefficients between LAeq, sharpness of the stimuli, and the 15 adjective scale values.
Fig 5.
Relationships between LAeq values and adjective scale values for “soft-loud”.
Fig 6.
Relationships between calculated sharpness and adjective scale values for “metallic-deep”.
Table 5.
Results of multiple regression analysis.
Table 6.
Correlation coefficients between adjective scale values and comfort index.
Fig 7.
Relationship between CI (LAeq/10+sharpness) and the adjective scale values ‘pleasing-unpleasing’ and ‘dislike-not dislike’.