DSL prescriptive targets for bone conduction devices: adaptation and comparison to clinical fittings

OBJECTIVE: To develop an algorithm that prescribes targets for bone conduction frequency response shape, compression, and output limiting, along with a clinical method that ensures accurate transforms between assessment and verification stages of the clinical workflow. DESIGN: Technical report of target generation and validation. STUDY SAMPLE: We recruited 39 adult users of unilateral percutaneous bone conduction hearing aids with a range of unilateral, bilateral, mixed and conductive hearing losses across the sample. RESULTS: The initial algorithm over-prescribed output compared to the user's own settings in the low frequencies, but provided a good match to user settings in the high frequencies. Corrections to the targets were derived and implemented as a low-frequency cut aimed at improving acceptance of the wearer's own voice during device use. CONCLUSIONS: The DSL-BCD prescriptive algorithm is compatible with verification of devices and fine-tuning to target for percutaneous bone conduction hearing devices that can be coupled to a skull simulator. Further study is needed to investigate the appropriateness of this prescriptive algorithm for other input levels, and for other clinical populations including those with single-sided deafness, bilateral devices, children and users of transcutaneous bone conduction hearing aids.