A new fitting-method for cochlear implant users based on stapedius-reflex measurements

Introduction In adult cochlear implant (CI) patients fitting is facilitated by verbal feedback to determine the threshold and most comfortable loudness level (MCL). This approach is not suitable for young children and patients unable to interact with the audiologist. In CI patients, an Electrically Evoked Stapedius Reflex Threshold (ESRT) can be determined in response to electrical stimulation through the implant. ESRT measurement does not require active feedback by the patient and can be obtained through a standard tympanometer. Still, nowadays this type of measurement is often unreliable because of technical shortcomings, which we aim to overcome. We implemented a setting that does not require pressurization of the ear canal and tested it in terms of accuracy and probe stability.

Materials & Methods We recruit adult patients, implanted with a MED-EL CI for at least 6 months. The patients undergo standard tympanometry and ESRT measurement. The results are then correlated with MCL determined by standard fitting. The measurements are then repeated by using the new dedicated probe.

Results So far 14 patients (6 male, 8 female) have been included in the study. The results obtained with the new setup are similar and sometimes more accurate than those obtained via standard tympanometry. Probe stability was generally improved compared to the standard probe fitting.

Conclusion Our data suggest that the development of a small, portable device capable of measuring ESRT without requiring ear canal pressurization may become a useful addition for CI patients unable to provide verbal feedback during fitting.

Conflict of Interest Der Erstautor weist auf folgenden Interessenkonflikt hin Damaris Platzer ist Mitarbeiterin der Firma MED-EL, die die Studie unterstützt.

Publication History

Article published online:
24 May 2022