Combined electric acoustic stimulation with the PULSARCI100 implant system using the FLEXEAS electrode array

Abstract

Conclusion: This study demonstrates that electric acoustic stimulation (EAS) using the FLEXEAS electrode is a successful treatment method for preservation and stability of low frequency hearing, and results in significant improvements in speech perception. Objectives: Low frequency hearing preservation and stability following EAS surgery with the MED-EL PULSARCI100 implant using the FLEXEAS electrode and a combined processor in a multicentre setting, and the efficacy and benefits of EAS over time were evaluated. Methods: Eighteen subjects with normal to moderate hearing loss in the low frequencies and severe to profound hearing loss in the high frequencies were implanted with the FLEXEAS electrode. Implantation was performed by different surgeons at three participating centres using either the cochleostomy or the round window approach. Preoperatively, hearing was measured; a battery of speech perception tests and the subjective benefit questionnaire were administered. These tests were subsequently repeated: first at EAS fitting, which was due 3 months after surgery, and then again 3, 6 and 12 months after EAS fitting. Results: Hearing could be preserved in all subjects. Speech understanding showed significant improvement in all tests over time with the EAS condition outperforming the cochlear implant-only condition at all intervals. These considerable effects were also reflected in the subjective benefit outcome.