title: Aided cortical response, speech intelligibility, consonant perception and functional performance of young children using conventional amplification or nonlinear frequency compression.
abstract: OBJECTIVE
  The aim of this study was to compare conventional processing with nonlinear frequency compression (NLFC) in hearing aids for young children with bilateral hearing loss.
  
  
  METHODS
  Sixty-four children aged between 2 and 7 years with bilateral hearing aids were recruited. Evaluations of cortical responses, speech intelligibility rating, consonant perception and functional performance were completed with the children wearing their personal hearing aids with conventional processing. The children were then refitted with new hearing aids with NLFC processing. Following a six-week familiarization period, they were evaluated again while using their hearing aids with NLFC activated.
  
  
  RESULTS
  The mean speech intelligibility rating and the number of cortical responses present for /s/were significantly higher when children were using NLFC processing than conventional processing in their hearing aids (p<0.05). Parents judged the children's functional real life performance with the NLFC hearing aids to be similar or better than that with the children's own hearing aids in both quiet and noisy situations. The mean percent consonant score was higher with NLFC processing compared to conventional processing, but the difference did not reach the 5% significance level (p=0.056). An overall figure of merit (FOM) was calculated by averaging the standardized difference scores between processing schemes for all measures. Regression analysis revealed that, on average, greater advantage for NLFC processing was associated with poorer hearing at 4 kHz.
  
  
  CONCLUSIONS
  Compared to conventional processing, the use of NLFC was, on average, effective in increasing audibility of /s/as measured by cortical evaluations, and higher ratings on speech intelligibility and functional performance in real life by parents. On average, greater benefits from NLFC processing was associated with poorer hearing at 4 kHz.
authors.affiliation: National Acoustic Laboratories, Sydney, Australia; HEARing CRC, Australia. Electronic address: vicky.zhang@nal.gov.au.
authors.forename: Vicky W
authors.initials: VW
authors.lastname: Zhang
authors.affiliation: National Acoustic Laboratories, Sydney, Australia; HEARing CRC, Australia.
authors.forename: Teresa Y C
authors.initials: TY
authors.lastname: Ching
authors.affiliation: National Acoustic Laboratories, Sydney, Australia; HEARing CRC, Australia.
authors.forename: Patricia
authors.initials: P
authors.lastname: Van Buynder
authors.affiliation: National Acoustic Laboratories, Sydney, Australia; HEARing CRC, Australia.
authors.forename: Sanna
authors.initials: S
authors.lastname: Hou
authors.affiliation: National Acoustic Laboratories, Sydney, Australia; Australian Hearing, Australia.
authors.forename: Christopher
authors.initials: C
authors.lastname: Flynn
authors.affiliation: National Acoustic Laboratories, Sydney, Australia; HEARing CRC, Australia.
authors.forename: Lauren
authors.initials: L
authors.lastname: Burns
authors.affiliation: National Acoustic Laboratories, Sydney, Australia; Australian Hearing, Australia.
authors.forename: Karen
authors.initials: K
authors.lastname: McGhie
authors.affiliation: National Acoustic Laboratories, Sydney, Australia; HEARing CRC, Australia.
authors.forename: Angela O C
authors.initials: AO
authors.lastname: Wong
mesh_terms: D002540:Cerebral Cortex / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D005072:Evoked Potentials, Auditory / Q000502:physiology; D005260:Female; D006309:Hearing / Q000502:physiology*; D006310:Hearing Aids; D006312:Hearing Loss, Bilateral / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010465:Perception; D013065:Speech Intelligibility / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology*
keywords: Children; Cortical evoked potentials; Hearing aids; Hearing loss; Nonlinear frequency compression; Speech perception