Atonal Interval.

摘要

Thresholds for the detection of the presence of a sinusoidal signal (thresholds of audibility) and thresholds for the perception of the tonal character of the signal (thresholds of tonality) were determined by three listeners over a wide range of audible frequencies. At each of the frequencies tested, the threshold of audibility was found to be significantly lower than the threshold of tonality. The difference between the two thresholds, the atonal interval, ranged from about 2.5 db at 500 c.p.s. to about 6.5 db at 4000 c.p.s. Little difference was found between the variabilities of the two thresholds. Preliminary measurements indicated that acuity of frequency discrimination changes quite abruptly at the threshold of tonality. Below the threshold of tonality frequency discrimination is very poor; above the threshold of tonality, frequency discrimination is markedly more acute.