Amplification of transcutaneous and percutaneous bone-conduction devices with a test-band in an induced model of conductive hearing loss

Objective: Transcutaneous devices have a disadvantage, the dampening effect by soft tissue between the bone and devices. We investigated hearing outcomes with percutaneous and transcutaneous devices using test-bands in an induced unilateral conductive hearing loss. Design: Comparison of hearing outcomes of two devices in the same individuals. Study sample: The right ear was plugged in 30 subjects and a test-band with devices (Cochlear? Baha® BP110 Power and Sophono® Alpha-2 MPO?) was applied on the right mastoid tip with the left ear masked. Sound-field thresholds, speech recognition thresholds (SRTs), and word recognition scores (WRSs) were compared. Results: Aided thresholds of Sophono were significantly better than those of Baha at most frequencies. Sophono WRSs (86?±?12%) at 40?dB SPL and SRTs (14?±?5?dB HL) were significantly better than those (73?±?24% and 23?±?8?dB HL) of Baha. However, Sophono WRSs (98?±?3%) at 60?dB SPL did not differ from Baha WRSs (95?±?12%). Conclusion: Amplifications of the current transcutaneous device were not inferior to those of percutaneous devices with a test-band in subjects with normal bone-conduction thresholds. Since the percutaneous devices can increase the gain when fixed to the skull by eliminating the dampening effect, both devices are expected to provide sufficient hearing amplification.