Intraoperative ABR measurements via the active middle ear implant vibrant soundbridge using different types of...

The Vibrant Soundbridge active middle ear implant is indicated for the treatment of different types of hearing loss. Recently, a novel system for determining implant performance based on auditory brainstem response (ABR) was developed. A reference value for the expected ABR hearing thresholds is determined on the base of a substantial number of measurements in this work.

ABRs were recorded in patients following VSB surgery. A standard ABR system was employed, utilizing an implemented optimized chirp stimulus, which was transmitted directly to the VSB via the AcoustiAP transmission unit (MED-EL). The study included 104 subjects with different types of hearing loss. Six distinct VSB couplers were utilized in this cohort.

ABR were recorded in all patients. The intraoperative ABR thresholds were 20.1 dB higher compared to the preoperative BC thresholds, 15.9 dB higher compared to the postoperative vibrogram, and 13.4 dB higher compared with the vibrogram thresholds determined at the first fitting. No significant differences were observed between the different couplers in either the investigated methods.

It can be posited that the presented intraoperative measurement reference value enhances the interpretability of ABR in VSB and should be considered, when using this method in VSB surgery.