title: Error Patterns Analysis of Hearing Aid and Cochlear Implant Users as a Function of Noise.
abstract: OBJECTIVE
  Not all impaired listeners may have the same speech perception ability although they will have similar pure-tone threshold and configuration. For this reason, the present study analyzes error patterns in the hearing-impaired compared to normal hearing (NH) listeners as a function of signal-to-noise ratio (SNR).
  
  
  METHODS
  Forty-four adults participated: 10 listeners with NH, 20 hearing aids (HA) users and 14 cochlear implants (CI) users. The Korean standardized monosyllables were presented as the stimuli in quiet and three different SNRs. Total error patterns were classified into types of substitution, omission, addition, fail, and no response, using stacked bar plots.
  
  
  RESULTS
  Total error percent for the three groups significantly increased as the SNRs decreased. For error pattern analysis, the NH group showed substitution errors dominantly regardless of the SNRs compared to the other groups. Both the HA and CI groups had substitution errors that declined, while no response errors appeared as the SNRs increased. The CI group was characterized by lower substitution and higher fail errors than did the HA group. Substitutions of initial and final phonemes in the HA and CI groups were limited by place of articulation errors. However, the HA group had missed consonant place cues, such as formant transitions and stop consonant bursts, whereas the CI group usually had limited confusions of nasal consonants with low frequency characteristics. Interestingly, all three groups showed /k/ addition in the final phoneme, a trend that magnified as noise increased.
  
  
  CONCLUSIONS
  The HA and CI groups had their unique error patterns even though the aided thresholds of the two groups were similar. We expect that the results of this study will focus on high error patterns in auditory training of hearing-impaired listeners, resulting in reducing those errors and improving their speech perception ability.
authors.affiliation: Department of Speech Pathology and Audiology, Graduate School, Hallym University, Chuncheon, Korea.
authors.forename: Hyungi
authors.initials: H
authors.lastname: Chun
authors.affiliation: Department of Speech Pathology and Audiology, Graduate School, Hallym University, Chuncheon, Korea.
authors.forename: Sunmi
authors.initials: S
authors.lastname: Ma
authors.affiliation: Division of Speech Pathology and Audiology, Research Institute of Audiology and Speech Pathology, College of Natural Science, Hallym University, Chuncheon, Korea.
authors.forename: Woojae
authors.initials: W
authors.lastname: Han
authors.affiliation: Soree Ear Clinic, Seoul, Korea.
authors.forename: Youngmyoung
authors.initials: Y
authors.lastname: Chun
keywords: Cochlear implants; Error pattern analysis; Hearing aids; Hearing impaired; Monosyllabic word test; Speech perception in noise