title: Benefit from non-linear frequency compression hearing aids in a clinical setting: the effects of duration of experience and severity of high-frequency hearing loss.
abstract: OBJECTIVE
  To determine whether non-linear frequency compression (NLFC) is effective for hearing-impaired adults in a clinical setting. To determine whether benefit from NLFC is related to duration of NLFC experience or severity of high-frequency hearing loss.
  
  
  METHODS
  Participants were fitted with Phonak frequency compression hearing aids as part of their standard clinical care, using the manufacturer's default fitting settings. Participants had been using NLFC for between 1 and 121 weeks at the time of testing. Speech recognition thresholds in noise and consonant recognition in quiet were measured with and without NLFC enabled.
  
  
  METHODS
  Forty-six experienced adult hearing-aid users.
  
  
  RESULTS
  Consonant recognition in quiet, but not speech recognition in noise was significantly better with NLFC enabled. There was no significant correlation between duration of frequency compression experience and benefit. Benefit for consonant recognition was negatively correlated with mean audiometric thresholds from 2-6 kHz.
  
  
  CONCLUSIONS
  NLFC was beneficial for consonant recognition but not speech recognition in noise. There was no evidence to support the idea that a long period of acclimatization is necessary to gain full benefit. The relation between benefit and high-frequency thresholds might be explained by the poor audibility of compressed information for some listeners with severe loss.
authors.affiliation: * School of Psychological Sciences, University of Manchester , Manchester , UK.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Hopkins
authors.forename: Mumtaz
authors.initials: M
authors.lastname: Khanom
authors.forename: Ann-Marie
authors.initials: AM
authors.lastname: Dickinson
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Munro
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D012048:Correction of Hearing Impairment / Q000295:instrumentation*; D003430:Cross-Sectional Studies; D004867:Equipment Design; D005260:Female; D006310:Hearing Aids; D006316:Hearing Loss, High-Frequency / Q000175:diagnosis / Q000523:psychology / Q000534:rehabilitation*; 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 / Q000534:rehabilitation*; D021641:Recognition, Psychology; D012720:Severity of Illness Index; D012815:Signal Processing, Computer-Assisted; D013061:Speech Acoustics; D013067:Speech Perception; D013069:Speech Reception Threshold Test; D013997:Time Factors