Relative satisfaction for frequency responses selected with a simplex procedure in different listening conditions.

The purpose of this study was to compare everyday satisfaction with hearing aid frequency responses selected using a Simplex procedure and those selected using the National Acoustic Laboratories' formula (NAL-R). Nineteen elderly subjects with impaired hearing selected their preferred frequency responses under six listening conditions. The conditions included syllable identification and discourse quality judgement in quiet, in moderate noise (65 dB SPL), and in loud noise (80 dB SPL) backgrounds. Subjects subsequently wore a multimemory hearing aid programmed with these frequency responses and compared their satisfaction with the various frequency responses in daily listening environments. Subjects showed differential preference across the available frequency responses. Subjects with sloping hearing losses did not show a difference in preference among the selected frequency responses, including that prescribed by NAL-R. On the other hand, subjects with a flat hearing loss showed a slight, but consistent, preference for frequency responses selected while listening to discourse passages in a moderate noise background. These observations suggest that the Simplex procedure may be useful for selecting preferred frequency responses for some hearing aid wearers.