Can audiometric results predict qualitative hearing improvements in bone-anchored hearing aid recipients?

Abstract

Patients receiving a bone-anchored hearing aid have well-documented improvements in their quality of life and audiometric performance. However, the relationship between audiometric measurements and subjective improvement is not well understood. Adult patients enrolled in the Nova Scotia bone-anchored hearing aid programme were identified. The pure tone average for fitting the sound-field threshold, as well as the better and worse hearing ear bone conduction and air conduction levels, were collected pre-operatively. Recipients were asked to complete the Speech, Spatial and Qualities of Hearing questionnaire; their partners were asked to complete a pre- and post-bone anchored hearing aid fitting Hearing Handicap Inventory for Adults questionnaire. Forty-eight patients who completed and returned the Speech, Spatial and Qualities of Hearing questionnaire had partners who completed the Hearing Handicap Inventory for Adults questionnaire. The results from the Speech, Spatial and Qualities of Hearing questionnaire correlated with the sound-field hearing threshold post-bone-anchored hearing aid fitting and the pure tone average of the better hearing ear bone conduction (total Speech, Spatial and Qualities of Hearing Scale to the pre-operative better hearing ear air curve (r = 0.3); worse hearing ear air curve (r = 0.27); post-operative, bone-anchored hearing aid-aided sound-field thresholds (r = 0.35)). An improvement in sound-field threshold correlated only with spatial abilities. In the Hearing Handicap Inventory for Adults questionnaire, there was no correlation between the subjective evaluation of each patient and their partner. The subjective impressions of hearing aid recipients with regards to speech reception and the spatial qualities of hearing correlate well with pre-operative audiometric results. However, the overall magnitude of sound-field improvement predicts an improvement of spatial perception, but not other aspects of hearing, resulting in hearing aid recipients having strongly disparate subjective impressions when compared to those of their partners.