Hearing Outcomes of a New Cartilage Conduction Device vs Bone Conduction Devices.

OBJECTIVE: To compare audiometric outcomes of a new cartilage conduction hearing device (CCD) with traditional bone conduction hearing devices (BCDs). STUDY DESIGN: Clinical trial and crossover study design. SETTING: Tertiary academic center. METHODS: Sixteen adults (19 ears) with congenital aural atresia or overclosed ear canals who previously underwent BCD implantation were fitted with a CCD. Audiometric data were collected with use of the BCD and the CCD. RESULTS: The mean pretreatment 4-frequency pure tone average was 81 dB. The mean aided pure tone averages with the BCD and CCD were 27 and 32 dB (P = .002), and the mean functional gains were 54 and 49 dB (P = .002), respectively. The mean consonant-nucleus-consonant scores with the BCD were 90% (best aided) and 80% (aided ear isolated), and those with the CCD were 86% and 76%. Mean AzBio scores were 90% (quiet), 77% (+10 dB SNR [signal to noise ratio]), and 52% (+5 dB SNR) when isolating the BCD ear and 90%, 73%, and 41% when isolating the CCD ear. No difference in speech scores achieved statistical significance except the AzBio isolated to the aided ear in the +5-dB SNR condition, which favored the BCD (P = .01). CONCLUSION: Pure tone audiometric outcomes with the BCD show a small advantage over the CCD, with the difference driven mainly by high-frequency responses. Speech outcomes were equivalent apart from the +5-db SNR condition, which favored the BCD.

Review of Bone Conduction Hearing Devices.

Bone conduction is an efficient pathway of sound transmission which can be harnessed to provide hearing amplification. Bone conduction hearing devices may be indicated when ear canal pathology precludes the use of a conventional hearing aid, as well as in cases of single-sided deafness. Several different technologies exist which transmit sound via bone conduction. Here, we will review the physiology of bone conduction, the indications for bone conduction amplification, and the specifics of currently available devices.