Electric stimulation complements functional residual hearing in partial deafness.

Conclusion: Candidates for hearing preservation cochlear implant (CI) surgery can be divided into: those who benefit from electrical complement (EC) to remaining hearing and don't require additional amplification, those using a combined electric-acoustic stimulation (EAS) and those with the least amount of residual hearing who benefit from electric-only stimulation (ES) provided via medium length electrode.

Objectives: Patients with a borderline level of residual hearing may benefit from a hybrid electric stimulation and acoustic amplification (EAS) after a cochlear implantation procedure aimed at hearing preservation. However, there is another group of individuals who possess substantial low-frequency residual hearing that is still functional. These partially deaf patients present a 'cliff-like' audiogram and have difficulty in comfortable listening, especially in noisy conditions and are deprived of the full enjoyment of music.

Methods: Eleven adults and seven children were implanted via round window with insertion depth intentionally limited to 18-22 mm. None of them could benefit from hearing aids before surgery and they were considered for EC to their residual hearing.

Results: Pure tone audiograms and discrimination scores show benefit from either EC to conserved natural acoustic hearing or EAS. One patient with a loss of functional residual hearing benefited from electrical stimulation (ES) and a standard CI coding strategy.