The intensity-difference limen for 6.5 kHz: an even more severe departure from Weber's law.
Intensity-difference limens (DLs) were obtained for tones of 6.5 kHz over levels of 30-90 dB SPL. The tones had Gaussian-shaped envelopes whose duration was expressed as equivalent rectangular duration D, that of a rectangle enclosing the same area as the envelope. D ranged from 0.314 to 30 msec. DL behaviors such as the "severe departure from Weber's law," the "midlevel hump," or the "midduration hump"--that is, a rise in the DL over a range of short durations--were identified using trend analysis. The DL versus level followed a "severe departure" that increased as duration dropped to D approximately 1-2 msec. That midlevel hump then fell with further shortening of the tone pip, producing a mid-duration hump. Materials for this article may be accessed through the Psychonomic Society's Norms, Stimuli, and Data archive, at www.psychonomic.org/archive.
Nizami
Lance
L
Boys Town National Research Hospital, Omaha, Nebraska, USA. nizamii2@aol.com
D000704:Analysis of Variance; D001288:Attention; D001309:Auditory Threshold; D002755:Choice Behavior; D004056:Differential Threshold; D005260:Female; D006801:Humans; D008144:Loudness Perception; D008297:Male; D016011:Normal Distribution; D010898:Pitch Perception; D011571:Psychoacoustics; D011930:Reaction Time; D013018:Sound Spectrography