Forward-masked monaural and interaural intensity discrimination.
Intensity-discrimination thresholds were measured for a 25-ms, 6-kHz pure tone for pedestal levels from 40 to 90 dB sound pressure level (SPL) with and without a forward masker (100-ms narrowband Gaussian noise, N(0)=70 dB). When the masker was present, the masker and probe were separated by 100 ms of silence. Unmasked and masked thresholds were measured in a two-interval monaural procedure and, separately, in a single-interval interaural procedure in which the pedestal and incremented pedestals were presented simultaneously to opposite ears. While the monaural thresholds were elevated markedly by the forward masker for mid-level pedestals, interaural thresholds were nearly unaffected by the masker across pedestal levels. The results argue against the notion that the monaural elevation in forward-masked thresholds is due to degraded encoding of intensity information at early stages of auditory processing.
Stellmack
Mark A
MA
Department of Psychology, University of Minnesota, Minneapolis, Minnesota 55455, USA. stell006@umn.edu
Viemeister
Neal F
NF
Byrne
Andrew J
AJ
D000328:Adult; D001307:Auditory Perception; D001309:Auditory Threshold / Q000502:physiology*; D002755:Choice Behavior; D004192:Discrimination, Psychological / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D010470:Perceptual Masking / Q000502:physiology*