To compare amplification options for patients with mixed hearing loss. Devices tested include percutaneous and transcutaneous bone conductors (BCDs) and middle ear implants with their actuator directly coupled to the cochlea.
Tertiary academic medical center.
Method and Participants
Maximum output was studied with simulators. As simulators are lacking for the middle ear implants (the Vibrant Soundbridge [VSB] and the Cochlear’s Direct Acoustic Cochlear Stimulator [Codacs]), the maximum output had to be measured in patients (4 and 5 patients, respectively).
Main Outcome Measure
The maximum output averaged at 0.5, 1, and 2 kHz was the main outcome measure, which was expressed in dB HL, using appropriate transformation tables.
The maximum output was the highest for the Codacs device and was above the patients’ uncomfortable loudness levels. The maximum output of the VSB varied between 65 and 85 dB HL, and that of percutaneous BCD varied between 68 and 80 dB HL depending on the type of device. The transcutaneous BCD, the Sophono device, had the lowest output.
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.