This paper presents a clinical procedure for optimising hearing aid amplification of severely and profoundly hearing impaired children. In this procedure, a paired comparison test was used to check whether an alternative frequency response was better than the NAL-RP prescription for speech intelligibility. A child wore a programmable hearing aid, and compared speech amplified using the NAL-RP prescription with alternative amplification schemes that provided either more low frequencies or less low and more high frequencies than the prescription. If no alternative frequency response was found to be better than the prescription, the prescription-based fitting was deemed to be optimal for the individual. In addition to paired comparison tests, home trials of alternative hearing aid settings were carried out for a small subgroup. During the trials, the children were tested using a phoneme identification task, and teachers' observations of the children's performance were recorded. These results support the paired comparison test results. Repeatability of intelligibility judgment was good for the children tested. Feedback from clinical audiologists indicate that the procedure was convenient to use, required about 21 minutes on average to test one ear, and was effective in improving fitting outcomes. The paired comparison test results suggest that the NAL-RP prescription provided a good starting estimate that was close to optimal for the children. Preferred frequency responses of 32 ears agreed with the prescription within +/- 6 dB/octave, and for the remaining two ears, frequency responses with more low frequency emphasis than the prescription were selected. On average, the children used 3 dB more gain (mean of 500, 1000 and 2000 Hz) than the NAL-RP prescription.
|Number of pages||13|
|Journal||Australian Journal of Audiology|
|Publication status||Published - 1999|