Patients with moderate-to-severe mixed hearing loss because of otosclerosis can benefit substantially using the Codacs investigational device.

Only with the Codacs device can the complete dynamic range be used. The maximum output of the VSB is lower and variable owing to the coupling to the cochlea. For patients with a sensorineural hearing loss component up to 50 dB HL, a percutaneous BCD forms a good treatment option that is completely independent of the middle ear status. The transcutaneous Sophono BCD is suitable for patients with a (sub-)normal sensorineural hearing loss component of 20 dB or less.

Long-term postoperative patient satisfaction and quality of life results show a significant difference compared with preoperative measurements, with conventional hearing aids. A negative trend over time is found on all questionnaires, which might reflect patient aging (increase of hearing loss) or habituation to a situation with fewer concerns regarding a patient's external otitis.

Medical and technical complications and device failures have mostly occurred in the initial period of active middle ear implants (AMEI) implementation and during clinical trials or experimental procedures. All four FIMOS had technical difficulties. An important decrease in the occurrence of both medical and technical complications was observed. Application in more recent years did not show any complications and the recent device failure rates are acceptable. Magnetic resonance imaging (MRI) incompatibility should be taken into account when indicating AMEI.