Hearing Outcomes After Cochlear Implant Surgery in Patients With Residual Hearing

Criteria for cochlear implantation (CI) have expanded to include patients with increasing amounts of residual acoustic hearing. The expectation of improved speech understanding exists with or without residual acoustic hearing; however, hearing preservation (HP) is of emerging relevance to CI surgeons. If low-frequency hearing (LFH) is preserved at aidable levels, patients typically have better performance in background noise and have a greater ability to appreciate music.¹

In 2022, Cleveland Clinic’s Hearing Implant Program used 4 different electrode arrays in hearing preservation cases: Cochlear Americas (Denver, Colorado) Cochlear™ slim perimodiolar array (Nucleus® 532 and 632), Nucleus slim lateral wall array (Nucleus 522, 622 and 624), Hybrid™ L24, and Advanced Bionics (Valencia, California) HiFocus™ Ultra 3D Midscala. The initial choice of platform was made by the patient. Surgeon preference or anatomy steered the choice of the perimodiolar or lateral wall arrays intraoperatively, except where patient specifically met Hybrid criteria. Whenever possible a round window insertion technique was used.

The Hearing Implant Program identifies CI candidates as having potential for HP if they have an aidable low-frequency (125–500 Hz) pure-tone average (LFPTA) ≤ 80 dB HL (hearing level). The average preoperative LFPTA for HP candidates in 2022 was 55.3 dB. Postoperative hearing thresholds were assessed 4 weeks after surgery.

Average change in hearing

2022 (N=78)

HP = hearing preservation

Of the total number of CIs performed in 2022, 56% of these were appropriate for HP.

Of the HP candidates with post-operative audiograms, 67% of these patients retained at least one frequency of 80 dB or better HL and 50% maintained a LFPTA <80 dB. The median change in LFPTA was similar for recipients with pre-curved vs lateral wall arrays (23 dB vs 22 dB).

  1. Woodson EA, Reiss LA, Turner CW, Gfeller K, Gantz BJ. The Hybrid cochlear implant: a review. Adv Otorhinolaryngol. 2010; 67:125-134.