Can we use Carina as a fully implantable hearing aid?
23 April 2019 (online)
The middle ear implant Carina® from CochlearTM is indicated for patients with sensorineural or mixed hearing loss. Primarily intended as a fully implantable hearing aid, patients are provided with the option to use of the external Button Audio Processor (BAP) to profit from additional amplification and reduced feedback.
Between 2017 and 2018, eight patients (6 female, 2 male, Ø 58.8 ± 11.5yrs.) with sensorineural (AC PTA4 = 68 dB HL; BC PTA4 = 60; n = 2) or mixed hearing loss (AC PTA4 = 80 dB HL; BC PTA4 = 46; n = 6) have been implanted with the Carina at the Medical School Hannover. During the surgeries, the microphones were positioned retroauricular on the mastoid (posterior inferior, n = 1; posterior, n = 6) or above the mastoid (n = 1). At the time of implant activation, 7 – 8 weeks after the surgery, we have fitted the implant to the patients' needs and satisfaction and determined the Freiburg monosyllable word recognition score (WRS) in quiet. Pre- and postoperative thresholds were used to detect potential changes in residual hearing and air-bone gap (ABG).
The mean residual hearing has been preserved after the implantation. A slight increase in the ABG was visible in patients with sensorineural hearing loss (ΔABGpost-pre = 11.7 dB). During the activation, three patients had to use a BAP because of strong feedback with the implant. The mean WRS improved from 0%/15% (unaided at 65/80 dB SPL) to 41%/79% (Carina at 65/80 dB SPL) and outperformed the preoperative WRS with conventional hearing aids (24%/58% at 65/80 dB SPL).
Most of the patients (62.5%) used the Carina as a fully implantable device. A further improvement of speech recognition is expected after a longer wearing time and acclimatization to the system and its sound.