Efficacy of frequency transposition on speech perception and production in hearing impaired Arabic-speaking children

Abstract

BackgroundA key objective when fitting hearing aids to children is to maximize the audibility of high frequency speech cues which are critical in the understanding of spoken language. Recent advances in digital signal processing have enabled the development of hearing aids which offer linear frequency transposition as a new way of accessing these important speech sounds. Transposition of acoustic information from higher to lower frequencies may help people with severe or profound high frequency hearing loss, especially when a ‘dead region’ is present. ObjectiveThe current study is designed to investigate the clinical efficacy of frequency transposition on speech perception in Arabic speaking hearing impaired children. MethodsTen children and adolescents with sensorineural hearing loss were evaluated with their own hearing aids, then fitted with Widex Inteo-19 with master program without frequency transposition. The study group was reevaluated after 2months to assess the benefits of the new digital HA, if any. HAs have been reprogrammed with a frequency transposition mode as a standalone program. The performance was compared with that of the former two visits after 3months of regular use and auditory training. ResultsHearing impaired children showed improvement in aided thresholds in the high frequency region. There was a significant improvement in the speech perception tests and in speech production as reflected on Voice Onset Time (VOT) of voiced stops and vowel duration. WILSI (Widex Infant Listening Skill Inventory) reflected the same improvement as judged by the parents. ConclusionHearing impaired children’s performance improved with frequency transposition program as evidenced by speech perception tests, speech production and WILSI questionnaire.