Evaluating the effectiveness of bone conduction hearing implants in rehabilitation of hearing loss

Implantable hearing devices are indicated for candidates who could not benefit from conventional hearing aids. This study aimed at evaluating their effectiveness in rehabilitation of hearing loss.

This study included patients who received bone conduction implants at Tertiary Teaching Hospitals, between December 2018 and November 2020. Data were collected prospectively, and patients were assessed both subjectively using COSI and GHABP questionnaires and objectively using bone conduction and air conduction thresholds, unaided and aided free field speech thresholds. Outcomes of transcutaneous (tBCHD) and percutaneous (pBCHD) bone conduction hearing devices were compared as well as outcomes of unilateral versus bilateral fitting. Postoperative skin complications were recorded and compared.

A total of seventy patients were included, thirty-seven of them were implanted with tBCHD and thirty-three with pBCHD. Fifty-five patients were fitted unilaterally compared to 15 bilateral fitting. Preoperative mean of bone conduction (BC) of the overall sample was 23.27 ± 10.91 dB, the Air conduction (AC) mean was 69.27 ± 13.75 dB. There was significant difference between unaided free field speech score (88.51% ± 7.92) and the aided score (96.79 ± 2.38) with P value = 0.00001. The postoperative assessment using GHABP showed a benefit score mean of 70.95 ± 18.79, patient satisfaction score mean of 78.15 ± 18.39. The disability score improved significantly from a mean of 54.08 ± 15.26 to residual score of only 12.50 ± 10.22 with P < 0.00001 postoperatively. There was significant improvement in all parameters of COSI questionnaire following fitting. Comparison of pBCHDs vs tBCHDs showed a non-significant difference regarding FF speech as well as GHABP parameters. Comparison of the post-operative skin complications was in favor of tBCHDs as (86.5%) of the patients had normal skin postoperatively, compared to 45.5% of patients with pBCHDs devices. Bilateral implantation showed significant improvement of FF speech scores, GHABP satisfaction score, as well as COSI score results.

Bone conduction hearing devices are effective solution for rehabilitation of hearing loss. Bilateral fitting yields satisfactory outcomes in suitable candidates. Transcutaneous devices carry significantly lower skin complication rates compared to percutaneous devices.