title: Cortical Evoked Potentials and Hearing Aids in Individuals with Auditory Dys-Synchrony.
abstract: OBJECTIVE
  The purpose of the present study was to investigate the relationship between cortical processing of speech and benefit from hearing aids in individuals with auditory dys-synchrony.
  
  
  METHODS
  Data were collected from 38 individuals with auditory dys-synchrony. Participants were selected based on hearing thresholds, middle ear reflexes, otoacoustic emissions, and auditory brain stem responses. Cortical-evoked potentials were recorded for click and speech. Participants with auditory dys-synchrony were fitted with bilateral multichannel wide dynamic range compression hearing aids. Aided and unaided speech identification scores for 40 words were obtained for each participant.
  
  
  RESULTS
  Hierarchical cluster analysis using Ward's method clearly showed four subgroups of participants with auditory dys-synchrony based on the hearing aid benefit score (aided minus unaided speech identification score). The difference in the mean aided and unaided speech identification scores was significantly different in participants with auditory dys-synchrony. However, the mean unaided speech identification scores were not significantly different between the four subgroups. The N2 amplitude and P1 latency of the speech-evoked cortical potentials were significantly different between the four subgroups formed based on hearing aid benefit scores.
  
  
  CONCLUSIONS
  The results indicated that subgroups of individuals with auditory dys-synchrony who benefit from hearing aids exist. Individuals who benefitted from hearing aids showed decreased N2 amplitudes compared with those who did not. N2 amplitude is associated with greater suppression of background noise while processing speech.
authors.affiliation: Department of Speech Pathology and Audiology, National Insitute of Mental Health and Neurosciences, Bangalore, India. drmjay16@gmail.com.
authors.forename: Pradeep
authors.initials: P
authors.lastname: Yuvaraj
authors.forename: Jayaram
authors.initials: J
authors.lastname: Mannarukrishnaiah
mesh_terms: D000293:Adolescent; D000328:Adult; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006310:Hearing Aids; D006313:Hearing Loss, Central / Q000503:physiopathology* / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D011930:Reaction Time; D012737:Sex Factors; D013067:Speech Perception; D055815:Young Adult