Masked level discrimination: deterring profile listening.
Two experiments examined how level discrimination (also called intensity discrimination) between two successive three-tone complexes depends on the bandwidth and rove range of a notched-noise masker. The three-tone complex consisted of equally intense components at 0.84, 1, and 1.17 kHz set to 25, 55, or 85 dB SPL. The notch extended from 0.77 to 1.27 kHz for all masker bandwidths. The masker level changed randomly on each presentation to reduce profile cues. Results from five listeners showed that level-discrimination thresholds, delta L's (= 20 log([p + delta p]/p), where p is pressure), increased somewhat as the rove range increased. In contrast to profile-discrimination experiments, the delta L's did not decrease with increasing masker bandwidth. In addition, when the rove range was 10 dB or larger, discrimination was generally better than the best possible performance by a profile observer. The results indicate that profile analysis is not essential for reasonably good level discrimination in the presence of notched-noise maskers.
Florentine
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Department of Speech-Language Pathology and Audiology (133FR), Northeastern University, Boston, Massachusetts 02115, USA.
Buus
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D000293:Adolescent; D000328:Adult; D001307:Auditory Perception; D004193:Discrimination Learning; D006801:Humans; D010470:Perceptual Masking