[First audiological results of the concha-worn bone conduction instrument C.A.I. BC811]

Diverse forms of bone conduction devices (BCD; percutaneous or transcutaneous) provide successful and well-established therapies for conductional hearing loss (CHL). For patients in whom a surgical procedure is to be avoided for medical or personal reasons, instruments with head straps or bands, and bone conduction glasses are available. The current article presents and examines the audiological results of a newly developed, nonsurgical bone conducting device (C.A.I. BC811, bruckhoff hannover; C.A.I: Concha Anchored Instrument) that is fixed in the concha and transfers the sound to the cheekbone.

In this cross-over study, 4 CHL patients with minimal sensorineural components and existing treatment with a BCD were supplied with a BC811. Audiological outcomes with the optimized existing device and the BC811 were evaluated and compared at 2-weekly intervals. In addition to the aided versus unaided sound field thresholds, the monosyllabic Freiburg intelligibility test, hearing in noise (OlSa) and the subjective benefit of the treatment (APHAB questionnaire) were investigated.

No significant differences between BC811 and the optimized existing devices were found in terms of aided thresholds in sound field, functional gain or monosyllabic intelligibility tests. The average aided improvement of the threshold was PTA4 = 29.4 ± 11.1 dB (mean ± standard deviation) with the BC811. The improvements in the monosyllabic intelligibility and hearing in noise tests were significant for both types of device and comparison between the device types revealed no significant differences. The subjective ratings of the perceived improvement reflected by the global APHAB score were positive and similar: 36.4 (control) and 33.4 (BC811).

The comparison with BCDs demonstrated that the BC811 is a realistic and audiologically sufficient alternative to surgical solutions using percutaneous devices for patients with CHL.