An easy method to determine crucial AMEI performance parameters from clinical routine data in individuals - Part 1: maximum output.

OBJECTIVE: The frequency specific maximum output (MO) of active middle ear implants is the most crucial parameter for speech intelligibility. We determined individual MO from clinical routine data in round window (RW) coupling of the Vibrant Soundbridge (VSB).

DESIGN: Monocentric, retrospective analysis.

STUDY SAMPLE: 68 ears implanted with the VSB at the RW were analysed. Using bone conduction and direct threshold, MO was determined for combinations of implants (VORP502, VORP503) and processors (Samba, Amadé). Coupling modes were: (A) without coupler (N = 28), (B) spherical coupler (N = 19), (C) soft coupler (N = 10) or (D) custom-made "Hannover coupler" (N = 11).

RESULTS: The MO frequency dependence was similar for coupling types (A-D) with a maximum at 1.5 kHz. No differences between groups were observed, although the average MO of the soft coupler was 10 dB lower. The average MO (0.5, 1.0, 2.0, 4.0 kHz) was (A) 77.6 ± 15.0 dB HL, (B) 81.0 ± 11.1 dB HL, (C) 67.6 ± 17.9 dB HL (C), and (D) 79.6 ± 11.7 dB HL (D).

CONCLUSION: The individual MO can be determined from patients' clinical data. It permits in-depth analyses of patient outcomes and definition of evidence-based indication and decision criteria.