Pure-tone intensity and frequency discrimination as a function of frequency and sensation level

Abstract

The most frequently cited data on intensity and frequency discrimination as a function of both frequency and sensation level are from Reisz (1928) and Shower and Biddulph (1931), respectively. Both of these experiments used modulated tones. Evidence has accumulated that the discriminable change is different for modulated and unmodulated tones. In the present experiment a 2IFC-adaptive procedure was used to estimate both ΔI and ΔF at eight frequencies from 200 to 8000 Hz and at five sensation levels from 5 to 80 dB. Subjects listened to 500-msec pure tones presented in low-level broad-band noise. Intensity discrimination was constant as a function of frequency, showing the same “near miss” to Weber's law at all frequencies. Frequency discrimination showed effects of both frequency and sensation level. [This research was supported by the National Institutes of Health.]