The Value Electrical Stapedial Reflex Thresholds (eSRTs) Cochlear Implant Mapping

Condition(s) studied

Investigational drug(s) / intervention(s)

ESR and ECAP measurements: Measurement of electrically evoked stapedial reflexes (ESRT) by stimulation via the cochlear implant. Measurement of the Electric compound action potentials (ECAPs) on the electrodes where the ESRT were performed. The measurements and tests will be performed during a routine visit to the Necker hospital for the adjustment of the cochlear implant (visit 1).

Device setting: The adjustment will be made by an audioprosthetist at the Center for Research in Audiology at Necker Hospital. The purpose of this setting is to modify the comfort thresholds using the ESR via a correction (according to the literature). The cochlear implant (CI) will therefore be set with the setting using the ESR (setting 2). The basic setting (setting 1) will be stored in memory in the CI. If ever the patient does not support setting 2, he/she will have the possibility of returning to the basic setting, without having to return to the Necker hospital for an additional setting. The measurements and tests will be done during an usual visit of the patient to the Necker hospital for the adjustment of the cochlear implant (visit 1).

Speech audiometry: This examination is part of the usual care for a patient with a cochlear implant. Fournier's monosyllabic test will be used. The test will be carried out by an audioprosthetist at the Center for Research in Audiology at Necker Hospital. The measurement will be performed under both setting conditions: setting 1 (current setting) and setting 2 (based on ESR). The order of administration will be randomized in order to overcome a training effect. The measurements and tests will be done during an usual visit of the patient to the Necker hospital for the adjustment of the cochlear implant (visit 1).

Intelligibility in noise test: The FraSimat is a measure of speech perception in noise. The test consists of 14 sentences of 3 words, recorded in the presence of background noise, which the child must listen to and repeat. The background noise remains fixed at 65dB HL and the speech intensity adapts according to the patient's responses. The measurement will be performed under two setting conditions: MAP 1 (current setting) and MAP 2 (setting based on ESR). The order of administration will be randomized in order to overcome a training effect. The measurements and tests will be done during an usual visit of the patient to the Necker hospital for the adjustment of the cochlear implant (visit 1).

Cochlear implant datalogging, speech audiometry test, FraSimat test: The follow-up visit (visit 2) will take place 1 month after visit 1 only for patients with a comfort levels threshold (via the eSRT) different from the current threshold (C-subjective). At the start of the visit, cochlear implant datalogging will be recorded to determine the use of both settings (setting 2, using the ESR and setting 1, basic setting) while wearing the cochlear implant. The datalogging will be recorded by an audioprosthetist at the Center for Research in Audiology at Necker Hospital. If the patient has worn the new program (setting 2), the speech audiometry test and the FraSimat test (Intelligibility in noise test) will be performed again with the setting based on ESR.

Study summary

One of the most significant challenges in cochlear implant programming, particularly for very young children and those with an associated pathologies, is the measurement of subjective comfort levels (= C-Subjective). Currently, to define this C-Subjective level, patients are presented with a loudness scale and must indicate whether the sound stimulus, sent via the implant, is soft, comfortable, or loud. The lower and upper stimulation levels must be determined for each electrode in order to program the implant. For many patients this can be difficult due to a lack of auditory experience and confusion between the sensation of sound intensity (weak or loud) and frequency (low or high).

A less commonly used but more objective approach to programming upper stimulation levels involves the use of the electrical stapedial reflex threshold (eSRTs) value. eSRTs are a promising measure, given the demonstrated correlation between the threshold that generates a stapedial reflex and the C-subjective level. Furthermore, eSRTs can be recorded in the majority of patients, and can typically be evoked at a comfortable stimulation level i.e. inferior to the uncomfortable level.

The main objective of this study is investigate the link between subjective comfort levels (C-subjective levels) and the eSRT.

Eligibility

Primary outcome measure(s)

• The relationship between the patient's current upper stimulation level (C-subjective) and the measured eSRT — Day 0
  Correlation between the patient's current upper stimulation level (C-subjective) and the measured eSRT measured at the visit 1.

Trial sites (1)

More Assistance Publique - Hôpitaux de Paris trials in France

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