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Totally Implantable Cochlear Implant (TICI): Feasibility Study

(Original title: Lefebvre, P.P., Müller, J., Mark, G. et al. Rehabilitation of human hearing with a totally implantable cochlear implant: a feasibility study. Commun Med 5, 10 (2025).)

Key message:

Safety, hearing performance and user satisfaction with the TICI are comparable to conventional cochlear implants.

Background

Cochlear implants (CIs) restore hearing in individuals with severe-to-profound hearing loss. Despite their proven benefits, CI uptake remains low. One reason is the external audio processor, its visibility, and its limitations for the user.

A totally implantable cochlear implant (TICI) was developed, combining all CI components in a single implant, invisible from the outside, eliminating the disadvantages of an external audio processor. The first-in-human study results of the TICI assessed its safety, hearing performance and user satisfaction.

Methods:

• Non-randomized single group assignment
• Participants:
  • 6 (4 female, 2 male) from 2 CI centers (Liège, Munich)
  • Mean age: 44.6 years
  • Bilateral severe to profound HL (>70 dB HL)
• Within-subject comparison with TICI and external audio processor
• Data collection over 52 weeks
• Surgery and fitting:
  • Standard surgical approach for conventional cochlear implants
  • First fitting 4 weeks post-op
• Outcome measures:
• Adverse events
• Speech perception in quiet (monosyllables) and in noise (sentence tests, SRT₅₀)
• Subjective quality of life, subjective sound quality (HUI3, SSQ-12, HISQUI-19, NCIQ)
• Subjective user satisfaction: diary reports
• Device usage (hours per day): TICI data logging

Results:

• Safety:
  • Adverse event distribution is comparable to conventional CIs.
  • Adverse events: 15, of which
    • Anticipated serious adverse device effect: 1 (swelling and infection signs at implantation site, successfully resolved without sequelae)
    • Unanticipated serious adverse device effects: 0

• Hearing performance and user satisfaction:
  • Speech perception in quiet and noise with the TICI was similar to the CI used with an external audio processor (within-subject comparison) as well as comparable to conventional CIs.
  • Patient-reported outcome measures and user satisfaction scores all increased over the study duration.
  • 5 of 6 participants used the TICI without an external processor most of the time.

Read the full paper here (Open Access): Rehabilitation of human hearing with a totally implantable cochlear implant: a feasibility study | Communications Medicine