title: Phonemic accuracy development in children with cochlear implants up to five years of age by using Levenshtein distance.
abstract: Phonemic accuracy of children with cochlear implants (CI) is often reported to be lower in comparison with normally hearing (NH) age-matched children. In this study, we compare phonemic accuracy development in the spontaneous speech of Dutch-speaking children with CI and NH age-matched peers. A dynamic cost model of Levenshtein distance is used to compute the accuracy of each word token. We set up a longitudinal design with monthly data for comparisons up to age two and a cross-sectional design with yearly data between three and five years of age. The main finding is that phonemic accuracy steadily increases throughout the period studied. Children with CI's accuracy is lower than that of their NH age mates, but this difference is not statistically significant in the earliest stages of lexical development. But accuracy of children with CI initially improves significantly less steeply than that of NH peers. Furthermore, the number of syllables in the target word and target word's complexity influence children's accuracy, as longer and more complex target words are less accurately produced. Up to age four, children with CI are significantly less accurate than NH children with increasing word length and word complexity. This difference has disappeared at age five. Finally, hearing age is shown to influence accuracy development of children with CI, while age of implant activation is not.
  
  
  OBJECTIVE
  This article informs the reader about phonemic accuracy development in children. The reader will be able to (a) discuss different metrics to measure phonemic accuracy development, (b) discuss phonemic accuracy of children with CI up to five years of age and compare them with NH children, (c) discuss the influence of target word's complexity and target word's syllable length on phonemic accuracy, (d) discuss the influence of hearing experience and age of implantation on phonemic accuracy of children with CI.
authors.affiliation: Computational Linguistics & Psycholinguistics (CLiPS) Research Centre, University of Antwerp, Belgium. Electronic address: jolien.faes@uantwerpen.be.
authors.forename: Jolien
authors.initials: J
authors.lastname: Faes
authors.affiliation: Mobile Vikings Belgium, Hasselt, Belgium. Electronic address: joris.gillis@gmail.com.
authors.forename: Joris
authors.initials: J
authors.lastname: Gillis
authors.affiliation: Computational Linguistics & Psycholinguistics (CLiPS) Research Centre, University of Antwerp, Belgium. Electronic address: steven.gillis@uantwerpen.be.
authors.forename: Steven
authors.initials: S
authors.lastname: Gillis
mesh_terms: D001184:Articulation Disorders / Q000175:diagnosis; D002675:Child, Preschool; D003054:Cochlear Implants; D005260:Female; D006801:Humans; D007805:Language Development Disorders / Q000175:diagnosis*; D008137:Longitudinal Studies; D008297:Male; D010699:Phonation; D010700:Phonetics; D012016:Reference Values; D013062:Speech Articulation Tests; D013065:Speech Intelligibility; D013067:Speech Perception; D013068:Speech Production Measurement
keywords: Children with CI; Levenshtein distance; Phonemic accuracy; Target word complexity; Target word syllable length