Using an interactive evolutionary algorithm to help fitting a cochlear implant

Cochlear implants are electronic devices that stimulate directly the auditory nerve to allow totally deaf patients to hear again. This paper presents an interactive evolutionary algorithm (IEA) designed to help finding the best parameters of a cochlear implant for a specific patient.If early cochlear implants only featured one electrode, modern devices now offer up to 22 electrodes, with the hope to be able to transmit more details and help the patient hear better. The work presented in this paper shows however that having more electrodes is not necessarily better.Tests on a patient show surprisingly that some combinations of electrodes yield better results than others, with the problem that there is no real way to determine which electrode is beneficial to speech understanding and which is not.The best result obtained by the patient on a speech understanding evaluation protocol was 48.5/100 after 10 years of fitting sessions by an expert practitioner. For many reasons explained in this paper, the evaluation of the best parameter setting found by the IEA in one day was 91.5/100.