title: Masking Period Patterns and Forward Masking for Speech-Shaped Noise: Age-Related Effects.
abstract: OBJECTIVE
  The purpose of this study was to assess age-related changes in temporal resolution in listeners with relatively normal audiograms. The hypothesis was that increased susceptibility to nonsimultaneous masking contributes to the hearing difficulties experienced by older listeners in complex fluctuating backgrounds.
  
  
  METHODS
  Participants included younger (n = 11), middle-age (n = 12), and older (n = 11) listeners with relatively normal audiograms. The first phase of the study measured masking period patterns for speech-shaped noise maskers and signals. From these data, temporal window shapes were derived. The second phase measured forward-masking functions and assessed how well the temporal window fits accounted for these data.
  
  
  RESULTS
  The masking period patterns demonstrated increased susceptibility to backward masking in the older listeners, compatible with a more symmetric temporal window in this group. The forward-masking functions exhibited an age-related decline in recovery to baseline thresholds, and there was also an increase in the variability of the temporal window fits to these data.
  
  
  CONCLUSIONS
  This study demonstrated an age-related increase in susceptibility to nonsimultaneous masking, supporting the hypothesis that exacerbated nonsimultaneous masking contributes to age-related difficulties understanding speech in fluctuating noise. Further support for this hypothesis comes from limited speech-in-noise data, suggesting an association between susceptibility to forward masking and speech understanding in modulated noise.
authors.affiliation: 1Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; and 2Department of Fonoaudiologia, Universidade Federal de Pernambuco, Recife/PE, Brazil.
authors.forename: John H
authors.initials: JH
authors.lastname: Grose
authors.forename: Denise C
authors.initials: DC
authors.lastname: Menezes
authors.forename: Heather L
authors.initials: HL
authors.lastname: Porter
authors.forename: Silvana
authors.initials: S
authors.lastname: Griz
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001307:Auditory Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise; D010470:Perceptual Masking / Q000502:physiology*; D013060:Speech; D013061:Speech Acoustics; D013067:Speech Perception; D013997:Time Factors; D055815:Young Adult