Feasibility and Reliability of Integrating Electrically Evoked Stapedius Reflex Threshold (eSRT) Measurement in a Pediatric Cochlear Implant Programming Center (eSRT2)

In children aged 0 to 7 years, behavioral evaluation during cochlear implant programming is often difficult or unreliable. Objective, reproducible, and rapid markers are therefore essential. While objective measures such as ECAP (electrically evoked compound action potentials) help guide safe programming, they can show inter-electrode and inter-subject variability. Electrically evoked stapedius reflex threshold (eSRT) has emerged as a relevant objective marker to approximate the comfort level of stimulation.

Pediatric studies indicate that eSRT can be measured in the majority of children, closely corresponds to the comfort level, and is associated with improved speech outcomes when programming is guided by eSRT. In our previous single-center study in children aged 8 to 17 years (N=30; 44 implanted ears), eSRT was obtained in 83.3% of patients, with strong correlation between C-subjective and C-eSRT thresholds (r>0.94; p<0.001) across all electrodes. Tonal performance remained stable, and speech intelligibility, particularly in noise (FraSiMat), significantly improved with an eSRT-based program after one month of habituation. Daily device use remained stable, reflecting good clinical acceptability. These results support the relevance of systematic integration of eSRT in routine programming.

The aim of the eSRT2 study is to evaluate the feasibility and reliability of eSRT measurement in real-world clinical care for children aged 0 to 7 years, and to monitor its stability during post-operative follow-up. Improved auditory accessibility and better-controlled acoustic comfort through eSRT are expected to accelerate speech development in children by enabling earlier improvements in vocal performance and intelligibility.

Study Overview

• Status: Not yet recruiting
• Conditions: Hearing Loss in Children With Unilateral or Bilateral Cochlear Implants
• Intervention / Treatment: Other: Electrically Evoked Stapedius Reflex Threshold (eSRT) Measurement

Detailed Description

Cochlear implant programming relies on determining the patient's auditory dynamic range. This corresponds to identifying, for each electrode, the threshold of first perception (T-level) and the most comfortable level of stimulation (C-level or MCL), which defines the functional stimulation range. Different implant manufacturers (Advanced Bionics, Cochlear, Med-El, Oticon Medical) provide specific recommendations for estimating these upper stimulation levels.

Programming can be performed using behavioral measures or objective measures. Behavioral methods, based on patient responses, are widely used in adults. In children and in patients with associated pathologies, behavioral measures are often difficult due to limited auditory experience and potential confusion between loudness and pitch perception.

Therefore, objective measures are recommended in pediatric populations to assist in programming. ECAP/EAP measures are commonly used but show variable performance depending on the measure and implant manufacturer

Another objective measure, the electrically evoked stapedius reflex threshold (eSRT), shows a strong relationship with comfort levels (C-level/MCL) in both adults and children. eSRT appears to be a relevant tool for guiding programming, especially when subjective measures are limited. Recent studies have optimized the protocol (probe frequencies, reproducibility criteria) and confirmed its feasibility , including in pediatric populations using high-frequency probes (Palani et al., 2022) and normative data in children (Aini, 2022). Combined approaches using ECAP and eSRT to estimate C-levels/MCL are also emerging in pediatric programming .

Functionally, better estimation of the comfort level improves auditory accessibility, which is associated with enhanced speech perception and vocal performance. Over the long term, this supports faster language development in children implanted early.

Our previous eSRT study in children over 8 years old demonstrated a strong correlation between C-subjective and C-eSRT thresholds, and improved speech intelligibility (particularly in noise, FraSiMat) with eSRT-guided maps. These findings support the integration of eSRT into routine programming for pediatric populations.

• Study Type: Observational
• Enrollment (Estimated): 48

Contacts and Locations

• Study Contact: Name: Sabrina BOUZAID; Phone Number: +33 01 87 89 29 14; Email: sabrina.bouzaid-ext@aphp.fr
• Study Contact Backup: Name: Aline DECHANET; Phone Number: +33 01 71 19 61 69; Email: aline.dechanet@aphp.fr

Study Locations

• France
  • Île-de-France Region
    • Paris, Île-de-France Region, France, 75015
      • Hôpital Necker Enfants Malades - Service d'ORL et chirurgie cervico-faciale

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The target population is pediatric children aged 0 to 7 years followed at a specialized center (Necker Hospital, Paris). In children under 7, cooperation with behavioral testing is often limited, making the use of robust objective markers crucial (Gordon et al., 2004).

Pediatric data suggest that eSRT can be measured in the majority of children and corresponds closely to the C-level (Lorens et al., 2004; Bresnihan et al., 2001; Aini, 2022), with recently optimized protocols (Palani et al., 2022; Wolfe et al., 2017).

The study includes children with unilateral or bilateral cochlear implants, across all implant manufacturers, reflecting real-world practice.

Exclusion of children with unstable middle ear pathology reduces the risk of false-negative eSRT results related to tympano-ossicular transmission.

Description

Inclusion Criteria:

• Child aged 0 to 7 years
• Unilateral or bilateral cochlear implant
• Normal tympanogram
• No objection from either parent or legal guardian

Exclusion Criteria:

• Severe neurological disorder present before inclusion (identifiable by MRI and/or pediatric neurological assessment)
• Unstable middle ear pathology on the day of inclusion (e.g., acute serous otitis, tympanic membrane perforation)
• Documented abnormality or lesion of the facial nerve or stapedius muscle
• Severe cognitive, psychiatric, or developmental delay at the day of inclusion
• Family not fluent in oral French.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
eSRT; All enrolled children (0-7 years) with unilateral or bilateral cochlear implants will undergo electrically evoked stapedius reflex threshold (eSRT) measurements during routine post-operative programming sessions at 3, 6, and 12 months. The eSRT measurement is complementary to standard programming procedures and does not replace any routine clinical care.	Other: Electrically Evoked Stapedius Reflex Threshold (eSRT) Measurement; During routine post-operative programming sessions (at 3, 6, and 12 months), each child will undergo eSRT measurement using a tympanometer placed in the ear canal

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To study the stability of eSRT over time at 3, 6, and 12 months: quantifying intra-subject / intra-ear stability of eSRT thresholds throughout follow-up	Success (per session) is defined as obtaining at least 3 usable eSRT measurements distributed across apex, middle, and base (≥1 electrode per third of the array), with a normal tympanogram and meeting the reproducibility criterion (≤5 machine units [MU] variation between two attempts on the same electrode).	3, 6, and 12 months post-implantation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To study the stability of eSRT over time at 3, 6, and 12 months: quantifying intra-subject/intra-ear stability of eSRT thresholds throughout follow-up	The variability of eSRT values must be < 5 machine units (MU) between each pair of visits (3↔6, 6↔12, and 3↔12 months).	3, 6, and 12 months post-implantation
To study the correlation between CeSRT and free-field tonal thresholds; association with speech performance (pediatric lists: Boorsmaa <4 years; Lafon ≥4 years - adjusted to the child's abilities; at the audiologist's discretion)	Correlation between CeSRT and free-field tonal thresholds will be evaluated. Associations with speech performance will be assessed using pediatric lists: Boorsmaa for children <4 years and Lafon for children ≥4 years, adjusted to the child's abilities and at the audiologist's discretion.	3, 6, and 12 months post-implantation
To document the burden of integrating eSRT into routine clinical practice	eSRT measurement time will be recorded from probe placement to the last usable measurement. Success and failure rates per session will be documented, along with the types of failure causes (non-cooperative child, artifacts, middle ear pathology, equipment/logistics issues).	3, 6, and 12 months post-implantation

Collaborators and Investigators

• Sponsor: Assistance Publique - Hôpitaux de Paris
• Collaborators: URC-CIC Paris Descartes Necker Cochin
• Investigators: Principal Investigator: Sabrina BOUZAID, Hôpital Universitaire Necker - Enfants Malades - Service d'ORL et chirurgie cervico-faciale

Study record dates

Study Major Dates

• Study Start (Estimated): February 15, 2026
• Primary Completion (Estimated): February 15, 2029
• Study Completion (Estimated): April 15, 2029

Study Registration Dates

• First Submitted: February 11, 2026
• First Submitted That Met QC Criteria: February 11, 2026
• First Posted (Actual): February 18, 2026

Study Record Updates

• Last Update Posted (Actual): February 25, 2026
• Last Update Submitted That Met QC Criteria: February 23, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Unilateral or bilateral cochlear implants; electrically evoked stapedius reflex threshold (eSRT)
• Additional Relevant MeSH Terms: Investigative Techniques; Weights and Measures
• Other Study ID Numbers: APHP251668; IDRCB (Other Identifier: 2025-A01568-41)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No