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

Conclusion: This study demonstrates that electric acoustic stimulation (EAS) using the FLEX<SUEAS</SU 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 PULSARCI<SU100</SU implant using the FLEX<SUEAS</SU 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 FLEX<SUEAS</SU 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.