title: Effects of inherent envelope fluctuations in forward maskers for listeners with normal and impaired hearing.
abstract: Gaussian noise simultaneous maskers yield higher masked thresholds for pure tones than low-fluctuation noise simultaneous maskers for listeners with normal hearing. This increased masking effectiveness is thought to be due to inherent fluctuations in the temporal envelope of Gaussian noise, but effects of fluctuating forward maskers are unknown. Because differences in forward masking due to age and hearing loss are known, the current study assessed effects of masker envelope fluctuations for forward maskers in younger and older adults with normal hearing and older adults with hearing loss. Detection thresholds were measured in these three participant groups for a pure-tone probe in quiet and in Gaussian and low-fluctuation noise forward maskers with either 1 or 1/3 equivalent rectangular bandwidths. Higher masked thresholds were obtained for forward maskers with greater inherent envelope fluctuations for younger adults with normal hearing. This increased effectiveness of highly fluctuating forward maskers was similar for older adults with normal and impaired hearing. Because differences in recovery from forward masking between listeners with normal and impaired hearing may relate to differences in cochlear nonlinearities, these results suggest that mechanisms other than cochlear nonlinearities may be responsible for recovery from rapid masker envelope fluctuations.
authors: Department of Speech-Language-Hearing Sciences, University of Minnesota, 164 Pillsbury Drive Southeast, Minneapolis, Minnesota 55455.
authors: Adam
authors: A
authors: Svec
authors: Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, 135 Rutledge Avenue, MSC 550, Charleston, South Carolina 29425.
authors: Judy R
authors: JR
authors: Dubno
authors: Department of Speech-Language-Hearing Sciences, University of Minnesota, 164 Pillsbury Drive Southeast, Minneapolis, Minnesota 55455.
authors: Peggy B
authors: PB
authors: Nelson
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000523:psychology; D001301:Audiometry, Pure-Tone; D001307:Auditory Perception; D001309:Auditory Threshold; D016022:Case-Control Studies; D003463:Cues; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects*; D017711:Nonlinear Dynamics; D010470:Perceptual Masking; D019986:Persons with Hearing Disabilities / Q000523:psychology*; D011571:Psychoacoustics; D013018:Sound Spectrography; D013997:Time Factors; D055815:Young Adult