Intensity discrimination in the presence of random-frequency, multicomponent maskers and broadband noise

Donna L. Neff, Walt Jesteadt

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

This study examined the effects of multicomponent, random-frequency maskers and broadband-noise maskers on intensity discrimination at 1000 Hz. Maskers and signals were 200 ms, presented simultaneously. In the first set of conditions, thresholds were measured for the detection of a 1000-Hz tone in the presence of 40 or 60 dB SPL random-frequency or noise maskers, with extensive training of listeners with the random-frequency masker to assure stable effects of masker-frequency uncertainty. The random-frequency maskers had two, six, or ten components chosen at random from a large frequency range (300-3000 Hz, excluding a 160-Hz band around 1000 Hz). For these maskers, performance across the four listeners was very similar, showing large effects of masker-frequency uncertainty. For noise maskers, performance matched predictions for energy-based masking. In the second and third sets of conditions, intensity discrimination was measured at 1000 Hz for pedestals ranging from 40 to 80 dB SPL, first in isolation and then in the presence of the maskers. The pattern of results for intensity discrimination in quiet showed the expected near miss to Weber's Law, but poorer performance than typically observed. The addition of broadband-noise maskers had little effect on performance. However, random-frequency maskers degraded performance in nearly all conditions, with the size of the effect dependent on the level of the pedestal relative to the masker. Considering the pedestal as a tonal masker, the data were fitted with various models of combined masking. A simple power-law model provided excellent fits, with exponents ranging from 0.24 to 0.35 for the multicomponent maskers, but 1.0 (linear) for the noise. The results support models positing that the effects of individual maskers undergo nonlinear transformation before they are added, independent of the mechanisms which produce these effects. Because random-frequency maskers presumably produce informational (uncertainty-based) masking, the nonlinearity in this case appears central rather than peripheral.

Original languageEnglish (US)
Pages (from-to)2289-2298
Number of pages10
JournalJournal of the Acoustical Society of America
Volume100
Issue number4
DOIs
StatePublished - Oct 1 1996

Fingerprint

discrimination
broadband
masking
Discrimination
isolation
education
frequency ranges
nonlinearity
exponents
thresholds
predictions
Uncertainty
Masking
Pedestal

ASJC Scopus subject areas

  • Arts and Humanities (miscellaneous)
  • Acoustics and Ultrasonics

Cite this

Intensity discrimination in the presence of random-frequency, multicomponent maskers and broadband noise. / Neff, Donna L.; Jesteadt, Walt.

In: Journal of the Acoustical Society of America, Vol. 100, No. 4, 01.10.1996, p. 2289-2298.

Research output: Contribution to journalArticle

@article{3bd083a5649e4b0aa8f9bb7a182233c1,
title = "Intensity discrimination in the presence of random-frequency, multicomponent maskers and broadband noise",
abstract = "This study examined the effects of multicomponent, random-frequency maskers and broadband-noise maskers on intensity discrimination at 1000 Hz. Maskers and signals were 200 ms, presented simultaneously. In the first set of conditions, thresholds were measured for the detection of a 1000-Hz tone in the presence of 40 or 60 dB SPL random-frequency or noise maskers, with extensive training of listeners with the random-frequency masker to assure stable effects of masker-frequency uncertainty. The random-frequency maskers had two, six, or ten components chosen at random from a large frequency range (300-3000 Hz, excluding a 160-Hz band around 1000 Hz). For these maskers, performance across the four listeners was very similar, showing large effects of masker-frequency uncertainty. For noise maskers, performance matched predictions for energy-based masking. In the second and third sets of conditions, intensity discrimination was measured at 1000 Hz for pedestals ranging from 40 to 80 dB SPL, first in isolation and then in the presence of the maskers. The pattern of results for intensity discrimination in quiet showed the expected near miss to Weber's Law, but poorer performance than typically observed. The addition of broadband-noise maskers had little effect on performance. However, random-frequency maskers degraded performance in nearly all conditions, with the size of the effect dependent on the level of the pedestal relative to the masker. Considering the pedestal as a tonal masker, the data were fitted with various models of combined masking. A simple power-law model provided excellent fits, with exponents ranging from 0.24 to 0.35 for the multicomponent maskers, but 1.0 (linear) for the noise. The results support models positing that the effects of individual maskers undergo nonlinear transformation before they are added, independent of the mechanisms which produce these effects. Because random-frequency maskers presumably produce informational (uncertainty-based) masking, the nonlinearity in this case appears central rather than peripheral.",
author = "Neff, {Donna L.} and Walt Jesteadt",
year = "1996",
month = "10",
day = "1",
doi = "10.1121/1.417938",
language = "English (US)",
volume = "100",
pages = "2289--2298",
journal = "Journal of the Acoustical Society of America",
issn = "0001-4966",
publisher = "Acoustical Society of America",
number = "4",

}

TY - JOUR

T1 - Intensity discrimination in the presence of random-frequency, multicomponent maskers and broadband noise

AU - Neff, Donna L.

AU - Jesteadt, Walt

PY - 1996/10/1

Y1 - 1996/10/1

N2 - This study examined the effects of multicomponent, random-frequency maskers and broadband-noise maskers on intensity discrimination at 1000 Hz. Maskers and signals were 200 ms, presented simultaneously. In the first set of conditions, thresholds were measured for the detection of a 1000-Hz tone in the presence of 40 or 60 dB SPL random-frequency or noise maskers, with extensive training of listeners with the random-frequency masker to assure stable effects of masker-frequency uncertainty. The random-frequency maskers had two, six, or ten components chosen at random from a large frequency range (300-3000 Hz, excluding a 160-Hz band around 1000 Hz). For these maskers, performance across the four listeners was very similar, showing large effects of masker-frequency uncertainty. For noise maskers, performance matched predictions for energy-based masking. In the second and third sets of conditions, intensity discrimination was measured at 1000 Hz for pedestals ranging from 40 to 80 dB SPL, first in isolation and then in the presence of the maskers. The pattern of results for intensity discrimination in quiet showed the expected near miss to Weber's Law, but poorer performance than typically observed. The addition of broadband-noise maskers had little effect on performance. However, random-frequency maskers degraded performance in nearly all conditions, with the size of the effect dependent on the level of the pedestal relative to the masker. Considering the pedestal as a tonal masker, the data were fitted with various models of combined masking. A simple power-law model provided excellent fits, with exponents ranging from 0.24 to 0.35 for the multicomponent maskers, but 1.0 (linear) for the noise. The results support models positing that the effects of individual maskers undergo nonlinear transformation before they are added, independent of the mechanisms which produce these effects. Because random-frequency maskers presumably produce informational (uncertainty-based) masking, the nonlinearity in this case appears central rather than peripheral.

AB - This study examined the effects of multicomponent, random-frequency maskers and broadband-noise maskers on intensity discrimination at 1000 Hz. Maskers and signals were 200 ms, presented simultaneously. In the first set of conditions, thresholds were measured for the detection of a 1000-Hz tone in the presence of 40 or 60 dB SPL random-frequency or noise maskers, with extensive training of listeners with the random-frequency masker to assure stable effects of masker-frequency uncertainty. The random-frequency maskers had two, six, or ten components chosen at random from a large frequency range (300-3000 Hz, excluding a 160-Hz band around 1000 Hz). For these maskers, performance across the four listeners was very similar, showing large effects of masker-frequency uncertainty. For noise maskers, performance matched predictions for energy-based masking. In the second and third sets of conditions, intensity discrimination was measured at 1000 Hz for pedestals ranging from 40 to 80 dB SPL, first in isolation and then in the presence of the maskers. The pattern of results for intensity discrimination in quiet showed the expected near miss to Weber's Law, but poorer performance than typically observed. The addition of broadband-noise maskers had little effect on performance. However, random-frequency maskers degraded performance in nearly all conditions, with the size of the effect dependent on the level of the pedestal relative to the masker. Considering the pedestal as a tonal masker, the data were fitted with various models of combined masking. A simple power-law model provided excellent fits, with exponents ranging from 0.24 to 0.35 for the multicomponent maskers, but 1.0 (linear) for the noise. The results support models positing that the effects of individual maskers undergo nonlinear transformation before they are added, independent of the mechanisms which produce these effects. Because random-frequency maskers presumably produce informational (uncertainty-based) masking, the nonlinearity in this case appears central rather than peripheral.

UR - http://www.scopus.com/inward/record.url?scp=0029798604&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029798604&partnerID=8YFLogxK

U2 - 10.1121/1.417938

DO - 10.1121/1.417938

M3 - Article

VL - 100

SP - 2289

EP - 2298

JO - Journal of the Acoustical Society of America

JF - Journal of the Acoustical Society of America

SN - 0001-4966

IS - 4

ER -