Intensity discrimination of pure tones is not a monotonic function of sensation level for frequencies above 6 kHz
Glenis R. Long, John K. Cullen · The Journal of the Acoustical Society of America · 1984
Some recent studies of intensity discrimination at high frequencies have reported that measures of intensity discrimination are nonmonotonically related to sensation level (SL) for frequencies between 6 and 10 kHz [Carlyon and Moore, J. Acoust. Soc. Am. Suppl. 1 73, S93 (1983); Cullen and Long, Abstr. Seventh Midwinter Research Meeting of ARO, 5 (1984)]. At these frequencies, difference limens estimated from amplitude modulation detection and pulsed tone discrimination are largest for stimuli near 30 to 40 dB SL. We have extended our studies to 14 kHz and obtained a more detailed characterization of this nonmonotonicity by measuring amplitude modulation detection thresholds for stimuli in 5-dB steps between 10 and 65 dB SL. Our data indicate that the larger difference limens reported by Florentine [J. Acoust. Soc. Am. 74, 1375–1379 (1983)] for high-SL high-frequency signals are found when the frequencies tested are near the upper limit of a subject's hearing. [Supported, in part, by Kam's Fund and Eye, Ear, Nose, and Throat Foundation of New Orleans.]