An Evaluation of Frequency Transposition for Hearing-Impaired School-Age Children
Deafness and Education International Volume 11, Number 2, ISSN 1464-3154
A 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 English. 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. This study examined the changes in aided performance observed in children with hearing impairment who trialed the alternative hearing aid technology. The rationale behind the research was to evaluate the benefits of this new technology, as applied in the commercially available Widex Inteo hearing aid, for a group of children with sloping high frequency sensori-neural hearing loss (n = 6). The participants were aged between 9 and 14 years and all attended mainstream schools. Outcome measures were comprised of tests of speech perception and speech production and questionnaires. Speech perception abilities were measured using CNC word and phoneme tests, with and without frequency transposition in both the audiovisual and visual alone modalities at 6 weekly intervals for 24 weeks. The Goldman-Fristoe 2 Test of Articulation was the chosen measure of speech production and was administered prior to the new aid fitting and after 24 weeks of frequency transposition use. Results showed statistically significant improvements for the group as a whole on both these measures. These results were supported by positive reporting on the questionnaires completed by key stakeholders. (Contains 4 tables and 1 figure.)
Smith, J., Dann, M. & Brown, P.M. (2009). An Evaluation of Frequency Transposition for Hearing-Impaired School-Age Children. Deafness and Education International, 11(2), 62-82.