title: Discrimination of the spectral density of multitone complexes.
abstract: Spectral density (D), defined as the number of partials comprising a sound divided by its bandwidth, has been suggested as cue for the identification of the size and shape of sound sources. Few data are available, however, on the ability of listeners to discriminate differences in spectral density. In a cue-comparison, forced-choice procedure with feedback, three highly practiced listeners discriminated differences in the spectral density of multitone complexes varying in bandwidth (W = 500-1500 Hz), center frequency (f(c) = 500-2000 Hz), and number of tones (N = 6-31). To reduce extraneous cues for discrimination, the overall level of the complexes was roved, and the frequencies were drawn at random uniformly over a fixed bandwidth and center frequency for each presentation. Psychometric functions were obtained relating percent correct discrimination to ΔD in each condition. For D < 0.02 Hz(-1), the steepness of the functions remained constant across conditions, but for D > 0.02 Hz(-1), they increased with D. The increase, moreover, was accompanied by a reduction in the upper asymptote of the functions. The data were well fit by a model in which spectral density discrimination is determined by the frequency separation of components on an equivalent rectangular bandwidth scale, yielding a roughly constant Weber fraction of ΔD/D = 0.3.
authors.affiliation: Auditory Behavioral Research Lab, University of Wisconsin, Madison, Wisconsin 53706, USA. stoelinga@wisc.edu
authors.forename: Christophe N J
authors.initials: CN
authors.lastname: Stoelinga
authors.forename: Robert A
authors.initials: RA
authors.lastname: Lutfi
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001299:Audiometry; D003463:Cues; D004192:Discrimination, Psychological; D030141:Feedback, Psychological; D005260:Female; D006801:Humans; D008962:Models, Theoretical; D010897:Pitch Discrimination; D011571:Psychoacoustics; D013018:Sound Spectrography; D013997:Time Factors; D055815:Young Adult
references.citation: Percept Psychophys. 1987 May;41(5):409-15
references.pmid: 3601622
references.citation: Percept Psychophys. 2001 Nov;63(8):1314-29
references.pmid: 11800459
references.citation: J Exp Psychol Hum Percept Perform. 2000 Feb;26(1):279-94
references.pmid: 10696618
references.citation: J Acoust Soc Am. 1997 Dec;102(6):3647-56
references.pmid: 9407656
references.citation: J Acoust Soc Am. 2004 Mar;115(3):1306-20
references.pmid: 15058353
references.citation: J Acoust Soc Am. 1993 Jan;93(1):452-61
references.pmid: 8423261
references.citation: J Acoust Soc Am. 2010 Jan;127(1):350-60
references.pmid: 20058982
references.citation: J Acoust Soc Am. 2001 Aug;110(2):1010-9
references.pmid: 11519569
references.citation: J Acoust Soc Am. 1986 Jun;79(6):1915-25
references.pmid: 3722601
references.citation: Percept Psychophys. 2001 Nov;63(8):1293-313
references.pmid: 11800458