| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device relaxing psychologically disagreeable noise by improving the frequency component distribution of noise generated during operation. SOLUTION: Among psychoacoustic parameters acquired from the noise of the relevant device at a position 1 m apart from an end face of the device, a condition that the value of sharpness is 2.7 acum or less is satisfied, and the values of loudness and tonality are adapted so that a discomfort index S can satisfy S<-0.6, where the discomfort index S is obtained by the following expression using the values of loudness and tonality: S=0.3135 × (loudness value) + 3.4824 × (tonality value) - 3.1460. |
