Noise-intensity discrimination: Effects of bandwidth conditions and mode of masker presentation

Abstract

Noise-intensity discrimination was studied as a function of both signal and masker bandwidth. Five bandwidths of noise—ranging from 100 to 10 000 Hz—were employed. Maskers were presented at each of three spectrum levels (5, 25, and 45 dB re 0.0002 μbar). Discrimination thresholds were relatively unaffected by changing bandwidth over a two-decade range when the signal and masker were filtered together, with either continuous or gated presentation of the masker. When the masker bandwidth was greater than that of the signal, the reciprocity between signal power density and signal bandwidth was found to be 5 dB per log unit of bandwidth with continuous maskers and 5–10 dB (depending upon level) with gated maskers. The results were compared with predictions of energy-detector models of noise-intensity discrimination. Modifications of simple energy-detection schemes were discussed. Subject Classification: [43]65.58, [43]65.75, [43]65.50; [43]50.70.

Musical intervals and relative pitch: Frequency resolution, not interval resolution, is special

“…Figure 2 displays the thresholds measured in the three tasks for each of the three dimensions. The basic discrimination thresholds we obtained were consistent with many previous studies ͑Schacknow and Raab, 1976;Jesteadt et al, 1977;Wier et al, 1977;Lyzenga and Horst, 1997;Micheyl et al, 2006b͒ and, as expected from signal detection theory ͑Micheyl et al, 2008͒, thresholds measured in the dual-pair task were somewhat higher than in the basic discrimination task. As has been found previously ͑Spiegel and Watson, 1984;Kishon-Rabin et al, 2001;Micheyl et al, 2006b͒, pitch discrimination thresholds were lower in subjects with more musical experience than in those with less, both for complex ͓F͑2,8͒ = 14.12, p = 0.002͔ and pure ͓F͑2,8͒ = 10.79, p = 0.005͔ tones, though this just missed significance for the dual-pair experiment, presumably due to the smaller subject pool ͓F͑2,6͒ = 5.08, p = 0.051͔.…”

Modeling auditory processing of amplitude modulation. II. Spectral and temporal integration

“…This has been interpreted in some former studies as the observers' ability to increase their effective bandwidth in detecting wideband signals ͑Green, 1960; Bos and de Boer, 1966;Schacknow and Raab, 1976͒. As already discussed by Viemeister ͑1979͒, the mechanism behind such a combination and the stage of processing where it occurs are still unclear.…”

Lütkenhöner’s „Intensity Dependence of Auditory Responses“: An Instructional Example in How Not To Do Computational Neurobiology

“…This turnabout seems especially odd in light of s o m e s h o r t c o m i n g s o f S D T t h a t w e r e n o t e d b y S w e t s , i n p a r t i c u l a r t h a t " t h e h u m a n observer, of course, performs less well than does the ideal observer in the great majority of detection tasks, if not in all" (p. 172). That finding has been replicated many times over; for intensity discriminability, for example, see deBoer (1966), Raab and Goldberg (1975), Schacknow and Raab (1976), Green and Swets (1988), Bernstein and Raab (1990), Buus (1990), Schneider (1997), andNizami (2005b), among others. In sum, Swets (1961) did not produce compelling evidence of an infinitely low threshold, thus leaving no reason to reject the notion, as expressed by Hellman and Zwislocki (1961, p. 687), that "The threshold of audibility is a natural boundary condition which cannot be eliminated".…”