Correlations Between Subjective and Objective Responses to Cochlear Implant Stimulation

NCT07371299 | Not Yet Recruiting

• 2 other identifiers: APHP2504862025-A01446-43
• Study Type: observational
• Target: 60
• Locations: 0 countries
• Sites: N/A

Brief Summary

Cochlear implants have been used for several decades, with major technological advances. However, adjustment can be difficult for patients who have to get used to a new sound that is electrical rather than acoustic. In general, adjustment is based on the patient's responses: the patient must inform the technician of their sensations in order to determine the sound level that is comfortable for them (MCL: maximum comfortable level). The adjustment therefore depends on a subjective assessment. The aim of the adjustments is to make the sound pleasant while increasing the stimulation level to the maximum tolerated level in order to achieve good listening dynamics. Objective indicators would therefore be useful in improving the accuracy of the adjustments. The objective measurements that can be taken are:

• Electrical compound action potentials (eCAP)
• Electrical auditory brainstem response (eABR)
• Electrical stapedius reflex threshold (eSRT).

Conditions

Severe to Profound Sensorineural Hearing Loss

Keywords

Cochlear implants; Cochlear implant stimulation; Electrical compound action potentials (eCAP); Electrical auditory brainstem response (eABR); electrical stapedius reflex threshold (eSRT)

Outcome Measures

Primary Outcomes (1)

• The MCL threshold, the objective response threshold (eSRT), the eSRT response

  "The MCL threshold, expressed in CU (charge unit) units, corresponds to the maximum level of stimulation of the implant required to obtain a sound level considered comfortable by the patient. It will be recorded at each post-operative check-up (M1, M3, M6, M9, and M12). The objective response threshold (eSRT), expressed in CU units, corresponds to the minimum level of implant stimulation required to elicit a stapedial reflex. It will be recorded at each post-operative assessment (M1, M3, M6, M9, and M12). The eSRT response will be collected using a tympanometry probe (commonly used to measure ear impedance in patients during a standard hearing assessment) in the patient's external auditory canal, ipsilateral or contralateral to the implanted side. The tympanometer will continuously record ear impedance during electrical stimulation until a significant variation is obtained, indicating the presence of the stapedial reflex."

  15 months

Secondary Outcomes (10)

• Correlation between behavioral MCL and eABR threshold

  Month 6 and Month 12 post-operative follow-up visits (incident cohort)

• Correlation between behavioral MCL and eCAP threshold

  M1, M3, M6, M9, M12 post-operative visits (incident cohort).

• Correlation between eSRT and eABR thresholds

  M6 and M12 post-operative visits (incident cohort).

• Correlation between eSRT and eCAP thresholds

  M1, M3, M6, M9, M12 post-operative visits (incident cohort).

• Correlation between eABR and eCAP thresholds

  Month 6 and Month 12 after cochlear implantation (incident cohort)

Study Arms (2)

Incident CI Cohort (Prospective Adults)

Adults ≥18 scheduled for first-time unilateral cochlear implantation within 3 months; followed post-op at M1, M3, M6, M9, M12. Objective measures on ≥3 electrodes (basal, middle, apical): eCAP via CI software; eABR via evoked-potential system; eSRT via tympanometer. No experimental intervention (routine programming only). Main interest: associations between objective metrics and behavioral MCL, with key analyses at M6 and M12.

Diagnostic Test: Objective electrophysiological measures (eCAP, eABR, eSRT)

Prevalent CI Cohort (Cross-Sectional Adults)

Adults ≥18 with unilateral cochlear implant use ≥12 months; single annual follow-up visit. Same objective measures (eCAP, eABR, eSRT) on ≥3 electrodes using standard clinical equipment; no intervention. Purpose: cross-sectional correlations and comparison with the incident cohort.

Diagnostic Test: Objective electrophysiological measures (eCAP, eABR, eSRT)

Interventions

Objective electrophysiological measures (eCAP, eABR, eSRT) DIAGNOSTIC_TEST

Non-invasive electrophysiological recordings obtained during/after routine cochlear-implant programming, using standard clinical equipment: eCAP via CI software, eABR via an evoked-potential system synchronized with the implant, and eSRT via tympanometry. No investigational device or randomization. Measurements are collected for observational correlations with behavioral levels. Schedule: incident cohort at M1, M3, M6, M9, M12; prevalent cohort single annual visit.

Incident CI Cohort (Prospective Adults); Prevalent CI Cohort (Cross-Sectional Adults)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adult patients who are going to receive or have received a cochlear implant.

You may qualify if:

• Incident case cohort:
• Age ≥ 18 years (18 years or older)
• Scheduled for first-time unilateral cochlear implantation within the next 3 months
• Informed about the study and did not object (non-opposition)
• Cross-sectional sample of prevalent cases:
• Age ≥ 18 years (18 years or older)
• Underwent unilateral cochlear implantation more than 1 year ago
• Informed about the study and did not object (non-opposition)

You may not qualify if:

• Prior middle or inner ear surgery
• Cognitive impairment or insufficient comprehension of French that would prevent understanding of study procedures or accurate measurement of comfort thresholds during programming
• Peripheral facial palsy
• Bilateral cochlear implantation
• Patient under legal guardianship/court-ordered protection
• \- More than half of the electrodes not inserted (i.e., \<50% electrode insertion)
• More than half of the electrodes not inserted (\<50% electrode insertion)
• Postoperative peripheral facial nerve palsy following the implantation surgery

Sponsors & Collaborators

• Assistance Publique - Hôpitaux de Paris: lead
• Cochlear: collaborator

Central Study Contacts

Antoine PAUL, PhD

CONTACT

+33145213128; antoine.paul@aphp.fr

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 19, 2025
• First Posted: January 27, 2026
• Study Start: January 15, 2026
• Primary Completion (Estimated): October 1, 2029
• Study Completion (Estimated): October 1, 2029
• Last Updated: January 27, 2026

Record last verified: 2025-12