Diagnosis of Problems Associated with Cochlear Implant Devices Seminar

Cochlear implants are highly successful medical prostheses, giving a sense of hearing to approximately half a million deaf people worldwide.  Babies may receive them around their first birthday and continue to use them for the rest of their lives.  Whilst the majority of devices continue to work well over a long period of use, between 3 and 5% of recipients require re-implantation within 10 years of the first surgery.  Problems may occur with the device, with the position of the electrodes or there may be an interaction between the device and the recipient’s ear.  In approximately 25% of cases, the cause of the problem leading to re-implant surgery is not established.

This seminar describes work undertaken by MSc Audiology students and staff at the University of Southampton Auditory Implant Service to establish if problems with the position of the electrode array can be identified by measuring cochlear implant electrode voltages using surface electrodes (REVS: Recording of Electrode Voltages on the Skin).  In the first experiment, the repeatability of the recordings, the effect of stimulation level and the position of the recording electrodes was investigated.  In the second experiment, the choice of stimulating electrodes was varied.  In both studies the effect of the position of the electrode array on the voltages was assessed.   The results of the experiments and their implications for clinical practise will be discussed.