Electric stimulation complements functional residual hearing in partial deafness

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.

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.

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.

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.