Electric Acoustic Versus Electric-Only Stimulation in Full-Length Lateral Wall Cochlear Array Recipients With Preserved Hearing.

Abstract

Objective: To determine if cochlear implant recipients who have low-frequency hearing preservation after surgery can benefit from electric-acoustic stimulation (EAS) even after a period of electric-only stimulation.

Study design: Prospective, crossover controlled, clinical study.

Setting: Private practice single-specialty clinic.

Patients: Patients who are native English speakers, implanted with a 28-mm lateral wall electrode, had residual low-frequency hearing post-cochlear implantation and had at least 3 months of electric-only stimulation before enrollment.

Intervention: Participants were reprogrammed from electric-only stimulation to EAS-A (with electric and acoustic overlap in the preserved frequencies) for 3 months. Outcomes were measured, and then the participants were changed to EAS-B, a non-overlap program. Outcomes and the patients' map preferences were recorded.

Main outcome measures: Speech perception for each programming strategy was measured with CNC and AzBio testing. Participants subjective performance was measured with CCIQ and APHAB testing for each modality.

Results: Out of a total of 117 consecutive CI patients with preoperative low-frequency hearing thresholds of at least 65 db HL, 43 (36.8%) had at least one low-frequency threshold less than 65 dB allowing the use of EAS. Twelve participants with 16 implanted ears were enrolled and completed the study. Statistical analysis showed that participants performed significantly better (p < 0.05) on CNC words with EAS-A (overlap, 71.6%) versus electric (65.5%) or EAS-B (non-overlap, 68%). There was not a difference between the strategies on AzBio testing. The overall scores on CCIQ and APHAB were also not statistically significant. A chi-squared test was performed for subjects' preferred programming strategy, revealing that there was a preference of the EAS strategies over electric only (p = 0.04).

Conclusions: There may be an advantage to EAS over electric-only stimulation in patients with low-frequency hearing preservation after cochlear implant even after a period of electric-only stimulation.