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Updated: May 14, 2026
06:04
Systematic Hearing Performance Evaluation Process for Adolescents with Cochlear Implantation at Early Ages
Published on: March 24, 2023
From nucleus 24 to 513: changing cochlear implant design affects auditory response thresholds
Karen A Gordon1, Blake C Papsin
1Archie's Cochlear Implant Laboratory, The Hospital for Sick Children, Toronto, Ontario, Canada. karen.gordon@utoronto.ca
Summary
Newer cochlear implant (CI) electrode designs, like the Nucleus 513, improve auditory nerve response thresholds. These advancements in CI technology offer better hearing outcomes for children, though not uniformly across all electrode positions.
Area of Science:
- Otolaryngology
- Biomedical Engineering
- Neuroscience
Background:
- Cochlear implants (CIs) are vital for hearing restoration in children with severe to profound hearing loss.
- Technological advancements in CI electrode design aim to improve auditory perception and neural response.
- Understanding the impact of different CI generations on auditory thresholds is crucial for optimizing patient outcomes.
Purpose of the Study:
- To compare auditory thresholds evoked by the Nucleus 513 research cochlear implant with those of previous generations from the same manufacturer.
- To evaluate the influence of evolving CI electrode design on auditory nerve response and behavioral thresholds in pediatric patients.
Main Methods:
- Prospective repeated measures study conducted at a tertiary pediatric hospital.
- 182 children receiving Nucleus cochlear implants (N24M, N24RCS, 24RE Freedom, N513 Leap) were included.
- Behavioral and auditory nerve response thresholds were measured using apical, mid-array, and basal electrodes in 203 ears.
Main Results:
- Auditory nerve thresholds generally decreased with newer CI devices, with apical electrodes showing the lowest thresholds.
- The newest devices (N24RE and N513) demonstrated the most significant threshold changes from the operating room to initial activation.
- Behavioral thresholds were lowest for the newest devices and decreased with age across all devices.
Conclusions:
- Evolving cochlear implant electrode design significantly impacts auditory thresholds in pediatric patients.
- Improvements in auditory thresholds are not uniform along the entire electrode array.
- These findings highlight the importance of electrode design in CI performance and suggest potential for further optimization.
Related Concept Videos
01:13The Cochlea
The cochlea is a coiled structure in the inner ear that contains hair cells—the sensory receptors of the auditory system. Sound waves are transmitted to the cochlea by small bones attached to the eardrum called the ossicles, which vibrate the oval window that leads to the inner ear. This causes fluid in the chambers of the cochlea to move, vibrating the basilar membrane.
01:15Auditory Pathway
Auditory pathways constitute the complex neural circuits responsible for transmitting and interpreting auditory information from the peripheral auditory system to the brain. Sound waves are initially captured by the outer ear, funneled through the ear canal, and reach the tympanic membrane (eardrum). These vibrations are transmitted via the middle ear's ossicles to the inner ear's cochlea.
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the...
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking the...
01:22Hair Cells
Hair cells are the sensory receptors of the auditory system—they transduce mechanical sound waves into electrical energy that the nervous system can understand. Hair cells are located in the organ of Corti within the cochlea of the inner ear, between the basilar and tectorial membranes. The actual sensory receptors are called inner hair cells. The outer hair cells serve other functions, such as sound amplification in the cochlea, and are not discussed in detail here.