title: Comparison of Multichannel Wide Dynamic Range Compression and ChannelFree Processing Strategies on Consonant Recognition.
abstract: BACKGROUND
  Both wide dynamic range compression (WDRC) and ChannelFree (CF) processing strategies in hearing aids were designed to improve listener comfort and consonant identification, yet few studies have actually compared them.
  
  
  OBJECTIVE
  To determine whether CF processing provides equal or better consonant identification and subjective preference than WDRC.
  
  
  METHODS
  A repeated-measures randomized design was used in which each participant identified consonants from prerecorded nonsense vowel-consonant-vowel syllables in three conditions: unaided, aided using CF processing, and aided using WDRC processing. For each of the three conditions, syllables were presented in quiet and in a speech-noise background. Participants were also asked to rate the two processing schemes according to overall preference, preference in quiet and noise, and sound quality.
  
  
  METHODS
  Twenty adults (seven females; mean age 69.7 yr) with ≥1 yr of hearing aid use participated. Ten participants had previous experience wearing aids with WDRC, and 10 had previous experience with CF processing. Participants were tested with both WDRC and CF processing.
  
  
  METHODS
  Number of consonants correct were measured and used as the dependent variable in analyses of variance with subsequent post hoc testing. For subjective preference, a listener rating form was employed with subsequent χ² analysis.
  
  
  RESULTS
  Overall results showed that signal-processing strategy did not significantly affect consonant identification or subjective preference, nor did previous hearing aid use influence results. Listeners with audiometric slopes exceeding 11 dB per octave, however, preferred CF processing and performed better in noise with CF processing.
  
  
  CONCLUSIONS
  CF processing is a viable alternative to WDRC for listeners with more severely sloping audiometric contours.
authors.affiliation: Department of Audiology and Speech Pathology, University of Tennessee Health Science Center, Knoxville, TN.
authors.forename: Patrick
authors.initials: P
authors.lastname: Plyler
authors.affiliation: Department of Audiology and Speech Pathology, University of Tennessee Health Science Center, Knoxville, TN.
authors.forename: Mark
authors.initials: M
authors.lastname: Hedrick
authors.affiliation: Department of Audiology and Speech Pathology, University of Tennessee Health Science Center, Knoxville, TN.
authors.forename: Brittany
authors.initials: B
authors.lastname: Rinehart
authors.affiliation: Department of Audiology and Speech Pathology, University of Tennessee Health Science Center, Knoxville, TN.
authors.forename: Rebekah
authors.initials: R
authors.lastname: Tripp
mesh_terms: D000368:Aged; D001301:Audiometry, Pure-Tone; D004867:Equipment Design; D005260:Female; D006310:Hearing Aids; D034381:Hearing Loss / Q000503:physiopathology / Q000523:psychology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise; D057240:Patient Preference; D012815:Signal Processing, Computer-Assisted; D013067:Speech Perception / Q000502:physiology*