Contralateral suppression in bimodal patients

Interaction between acoustic and electrical stimulation in bimodal patients (BP) is of major interest as it influences speech understanding in everyday situations. Contralateral suppression is an important strategy in binaural hearing: If noise is presented to one ear, efferent signals of the contralateral Nucleus olivaris medialis are provided to inhibit input of the noise-related ear. Mechanisms of contralateral suppression in patients with a hearing aid (HA) in one ear and a cochlear implant (CI) in the other have not yet been investigated.

Methods Calibration of acoustic and electrical suppression signal was completed by testing healthy volunteers. 21 BP were enrolled. Experimental setup for BP was: 1. E-BERA (click) on CI deducted while playing an acoustic suppression signal on HA side 2. acoustic BERA (click) deducted on HA side while playing an electrical suppression signal on CI side. Speech understanding in quiet and in noise was assessed.

Results Reproducible recordings were successfully conducted. In some patients an increase of wave V potential was determined when electrical suppression signal presented on the contralateral CI side. In patients with a good performance of speech understanding in quiet and noise this effect seems to be more distinct. Preoperative duration of deafness seems to influence measurement outcomes.

Conclusion The experimental setup presented in this study can be used to measure contralateral suppression in BP. However, contralateral suppression presents less distinct in BP. Duration of deafness and degree of hearing loss on HA side seem to be important factors of contralateral suppression.

Poster-PDF A-1291.pdf

Cochlear Limited

Conflict of interest

Der Erstautor gibt keinen Interessenskonflikt an.

Publication History

Article published online:
13 May 2021