Abstract
Objective
In patients with conductive (CHL) or mixed hearing loss (MHL), hearing rehabilitation with an implantable hearing system, active middle ear implant (AMEI) or a semi-implantable bone-conduction device (SIBCD), is an option when conventional hearing aids are insufficient, or patients are unable to wear them.
Design
Retrospective analysis of 20 consecutive patients (24 implants) with a comparison of demographic characteristics and audiometric results (air-bone gap = ABG, effective hearing gain = EHG, functional hearing gain = FHG, Freiburg Monosyllabic Test in quiet, Oldenburg Sentence Test in noise = OLSA).
Study sample
Patients, eligible for both devices, who received either AMEI or SIBCD due to CHL or MHL.
Results
Analysis showed no significant differences in post-operative functional hearing results between the group of AMEI vs. SIBCD (ABG-reduction: 31.6 ± 12.4 dB HL vs. 28.0 ± 11.8 dB HL; p = 0.702; EHG: −1.6 ± 7.7 dB HL vs. −1.2 ± 4.2 dB HL; p = 0.090; FHG: 33.4 ± 12.6 dB HL vs. 26.1 ± 11.7 dB HL; p = 0.192; Freiburg: 83.0 ± 15.6% vs. 83.6 ± 14.2%; Freiburg-improvement: 57.7 ± 26.8% vs. 68.2 ± 19.7%; p = 0.294; OLSA: −2.7 ± 3.0 SNR vs. −1.4 ± 3.6 SNR; OLSA-improvement: 2.6 ± 2.1 dB vs. 3.7 ± 2.8 dB; p = 0.323). Four patients had the AMEI explanted due to insufficient functioning and later received a SIBCD.
Conclusions
Due to more challenging anatomical conditions, a surgical technique for the AMEI is more complex. However, functional results are comparable to the SIBCD. Therefore, proper patient counselling and cautious choice of the device are mandated before surgery.
Acknowledgements
The authors would like to thank Jenny Blum, Nadine Dietrich (née Herrmann), Jeannine Müller, and Stefan Thom for expert technical assistance. This work is part of the doctoral thesis of Laura Volbers.
Author contributions
JLS analysed data and wrote the paper. BGW, MB, and MC conceptualised the study and provided critical revision. IS analysed data and provided critical revision. FI designed the experiments, collected and analysed data, and provided critical revision. All authors discussed the results and implications and commented on the manuscript at all stages.
Disclosure statement
Jennifer L. Spiegel received travel expenses to one conference in Austria in 2019 from MED EL, GmbH, Innsbruck, Austria. The authors state not to have received any funding from the following institutions: National Institutes of Health (NIH), Wellcome Trust, or Howard Hughes Medical Institute (HHMI).