Electrocochleography Along Cochlear Implant Auditory Rehabilitation

Electrocochleography (eCochG) is an electrophysiological measurement to evaluate the activity of cochlear hair cells in response to acoustic stimulation. This measure thus reflects the functional state of the cochlea and more specifically the neuronal survival.

Whereas in the normal-hearing subject, eCochG collection requires the introduction of a collection electrode in the middle ear, closest to the cochlea, in the cochlear implant subject, eCochG can be collected through the electrodes of the cochlear implant.

Measured during surgery, eCochGs may help optimize the placement of the electrode array within the cochlea and help in the decision to refer the patient to a conventional cochlear implant or, when residual cochlear activity is detected, to an electro-acoustic implant system.

The main objective of this study is to evaluate the usefulness of intra-operative eCochG collections for the optimization of electrode array placement within the cochlea and then for monitoring the residual hearing and its relationship to hearing performance during the first months of rehabilitation.


Eligibility Criteria:
Inclusion Criteria:

1. Subjects, male or female, aged 8 to 75 ;
2. Candidates for cochlear implantation with measurable residual hearing?
3. French must be the mother tongue and is (or has been) the language of schooling;
4. No ototoxic or neurotropic drug treatment (epilepsy, behavioral disorders, other neurological impairment);
5. No known cognitive disorders, neurodegenerative disorders (Alzheimer's, Parkinson's, ...), psychiatric pathologies (depression, schizophrenia, eating disorders, ...) or neurodevelopmental disorders (attention deficit disorder with or without hyperactivity, autism spectrum disorder, specific learning disorder);
6. Absence of uncorrected visual problems;
7. Normal ENT examination;
8. Valid membership in a social security system;
9. Non-participation in another study;
10. Absence of exposure to loud noise in the 72 hours preceding the experiments;
11. Written consent to free and informed participation signed by the subject and his/her legal guardians in the case of minors.

Exclusion Criteria:

1. Absence of signature of the informed consent by the adult subject and/or the parents of the minor subject ;
2. Subjects speaking a foreign language at home and/or whose schooling was conducted in a foreign language (except for subjects attending bilingual schools and one of whose parents' usual language is French);
3. Subjects undergoing ototoxic or neurotropic drug treatment (epilepsy, behavioural disorders, other neurological impairment);
4. Subjects suffering from cognitive deficits, neurodegenerative disorders (Alzheimer's, Parkinson's, ...), psychiatric pathologies (depression, schizophrenia, eating disorders, ...) or neurodevelopmental disorders (attention deficit disorder with or without hyperactivity, autism spectrum disorder, specific learning disorder);
5. General state of health incompatible with the protocols;
6. Disability(ies) associated with deafness (deaf-blindness, ...) ;
7. Exposure to intense noise in the 72 hours preceding the experiment.
8. Non-affiliation to a social security system.
9. Pregnant or breastfeeding woman
10. Subjects deprived of liberties