BACKGROUND: There is no consensus on treatment of patients with congenital unilateral aural atresia. Currently, 3 intervention options are available, namely, surgical reconstruction, application of a bone-conduction device (BCD), or application of a middle ear implant. OBJECTIVE: The present study aims to compare the BCD with the application of a middle ear implant. We hypothesized that cross-hearing (stimulating the cochlea by means of bone conduction contralateral to the implanted side) would cause BCD users to have difficulty performing localization tasks. METHODS: Audiologic data of 4 adult patients with a middle ear implant coupled directly to the cochlea were compared with data of 4 adult patients fitted with an osseointegrated BCD. All patients were fitted during adulthood. The emphasis of this study is on directional hearing. RESULTS: The middle ear implant and the BCD improved sound localization of patients with congenital unilateral aural atresia. Unaided scores demonstrate a large variation. CONCLUSION: Our results demonstrate that there was no advantage of the middle ear implant over the BCD for directional hearing in patients who had no amplification in childhood. The BCD users had the best bandwidth.