Simultaneous bilateral transcutaneous bone conduction device implantation: sound localisation and speech perception in children with bilateral conductive hearing loss.

OBJECTIVE This study investigated the audiometric and sound localisation results in patients with conductive hearing loss after bilateral Bonebridge implantation. METHOD Eight patients with congenital microtia and atresia supplied with bilateral Bonebridge devices were enrolled in this study. Hearing tests and sound localisation were tested under unaided, unilateral and bilateral aided conditions. RESULTS Mean functional gain was higher with a bilateral fitting than with a unilateral fitting, especially at 1.0-4.0 kHz (p < 0.05, both). The improvement in speech reception threshold in noise with a bilateral fitting was a 2.3 dB higher signal-to-noise ratio compared with unilateral fitting (p < 0.05). Bilateral fitting had better sound localisation than unilateral fitting (p <0.001). Four participants who attended follow up showed improved sound localisation ability after one year. CONCLUSION Patients demonstrated better hearing threshold, speech reception thresholds in noise and directional hearing with bilateral Bonebridge devices than with a unilateral Bonebridge device. Sound localisation ability with bilateral Bonebridge devices can be improved through long-term training.