Can we use Carina as a fully implantable hearing aid?

Introduction:

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.

Method:

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).

Results:

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).

Conclusion:

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.

Publication History

Publication Date:
23 April 2019 (online)