Abstract
According to the acoustical method adopted herewith, the 2kHz pure tone that travels with a duration of 20msec followed by the tone of the same frequency is given as the acoustical stimulus and the time interval between the two is adjusted in such a way as to bring about psychological fusion of the two tones, each subject being asked to give his differential threshold value τ_m. In the same way, the subject's differential threshold value φ_m of the flicker fusion technique is also obtained. Data based on 7 subjects. The analysis of the relation between the degree of fatigue and τ_m and φ_m indicates that τ_m and φ_m are both related to the degree of fatigue and that the τ_m and the φ_m stand almost in the reverse relation to each other as to the fatigue degree. Factors that contribute to τ_m or φ_m are analyzed and the degree of their contribution is determined by the Quantification Theory I. τ_m and φ_m have generally negative correlation coefficients to each other, but as to the fatigue state, they stand to each other in positive relations. The average τ_m per day of the week and the frequency of incidence of fatigue per day of the week (F_p) stand in correlational relations to each other, but the correlation coefficients of τ_m are greater for young adolescents while those of φ_m tend to be greater for elder people.
