An interventional study of Cochlear Implant in Single Sided Deafness, Unilateral Deafness and Hearing Loss, Unilateral, sponsored by University of North Carolina, Chapel Hill. Recruiting at 1 site in United States. Open to participants aged 7 Months to 71 Months, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-26.
Sponsored by University of North Carolina, Chapel Hill · Not applicable, Interventional, and Other
The goal of this clinical trial is to investigate the safety and effectiveness of cochlear implantation in infants and toddlers with single-sided deafness.
The main questions it aims to answer are:
Participants will receive a cochlear implant and be followed until they are five years old. During those five years, the investigators will program the device and monitor auditory development.
Children will be asked to:
The researchers will compare results to children with typical hearing in both ears and children with single-sided deafness who have not received an implant to observe any differences between the groups.
Cochlear implantation is an FDA-approved option for children with single-sided deafness (SSD) who are over the age of five years. It has been well established that early implantation is advantageous for children with bilateral hearing loss as it takes advantage of the narrow window of neural plasticity. Research has yet to show the ideal age for implantation in children with SSD but considering the known impacts of age at implantation and duration of deafness on cochlear implant (CI) outcomes, five years is likely a late age for implantation in a child with congenital SSD. The purpose of this prospective clinical trial is to evaluate the safety and effectiveness of cochlear implantation in infants and toddlers with SSD.
Twenty (20) infants and Toddlers with SSD who are under the age of three will receive a cochlear implant. They will be followed until they reach the age of five. A group of typically hearing five-year-olds (n=20) and a group of five-year-olds with congenital or early onset SSD who have not received a cochlear implant (n=20) will also be recruited. All three groups of five-year-olds will be tested on measures of hearing in quiet, localizing, and hearing in spatially separated noise for comparison. Scores from the study group and the SSD control group will be compared to evaluate effectiveness.
The study will also explore the potential effects of SSD and early implantation on language, sensory processing, executive function, fatigue, and cognition.
To be eligible to participate in this trial as a study subject, an individual must meet all of the following criteria:
Unilateral severe-to-profound sensorineural hearing loss, congenital or acquired prior to the age of 2 years, defined as:
i. Thresholds should be measured using inserts wherever possible, or in the sound field to record the better-hearing ear alone. Required thresholds will include 250, 500, 1000, 2000, and 4000 Hz for air conduction. All other octave frequencies should be attempted. Bone conduction thresholds should be obtained at 500, 1000, 2000, and 4000 Hz. Masking should be attempted where appropriate. As participants are very young and masking is difficult for this population, suspected shadow audiograms will be sufficient if objective testing has confirmed a severe-to-profound unilateral hearing loss. Testing should confirm a severe-to-profound hearing loss, defined as a 3-frequency PTA (500, 1000, and 2000) >70 dB HL in one ear and ≤20 dB HL in the contralateral ear. The Primary Investigator and Lead Diagnostic Audiologist must agree on this diagnosis for enrollment.
Insufficient functional access to sound with appropriately fit amplification and aural habilitation (based on best practices and standard of care) defined as:
To participate as an SSD control subject, an individual must meet all the following criteria:
Unilateral severe-to-profound hearing loss - congenital or acquired prior to 2 years of age.
To participate as a TH control subject, an individual must meet all the following criteria:
An individual who meets any of the following criteria will be excluded from participation in this study as a study subject:
English is not primary language of the home
An individual who meets any of the following criteria will be excluded from participation in this study as a control subject:
English is not primary language of the home
This group of children with single-sided deafness will receive a cochlear implant.
Device: Cochlear Implant
This group of five-year-old children will have typical hearing in both ears.
This group of five-year-old children will have single-sided deafness and no cochlear implant.
A cochlear implant is a surgically implanted device that provides access to sound in people cannot get enough access to sound for communication with traditional hearing aids.
Also known as: MED-EL SYNCHRONY 2 Cochlear Implant
Mean Difference in the Signal-to-Noise Ratio 50 (SNR-50) between the Study Group and SSD Control Group as Measured with the BKB-SIN at 5 Years of Age
Two ½ lists of the Bamford-Kowal-Bench Speech in Noise Test (BKB-SIN) will be presented in a single condition: speech in front and masker directed 90 degrees to the normal ear. The SNR-50 represents the signal-to-noise ratio required to perceive 50% of the sentence. A lower score is better. All participants will be 5 years old at the time of testing. The study group will use their cochlear implant in conjunction with the normal hearing ear. The SSD control group will use their normal hearing ear alone.
Time frame: 5 years of age
Mean Difference in Localization Error Between the Study Group and the SSD Control group Measured at 5 Years of Age
Soundfield localization of 200-ms speech-shaped noise, presented from 11 speakers at 70 decibel (dB) sound pressure level (SPL) in a sound treated room. Overall root-mean-square (RMS) error is the difference between the sound source azimuth and the response azimuth and a lower score indicates more accurate localization of the sound source. All participants will be 5 years old at the time of testing. The study group will use their cochlear implant in conjunction with the normal hearing ear. The SSD control group will use their normal hearing ear alone.
Time frame: 5 years of age
Proportion of Procedural Related Adverse Events 6 months after Surgery
Procedural adverse events will be collected and reported as the proportion of subjects experiencing them.
Time frame: 6 months after surgery
Proportion of Device-Related Adverse Events 6 Months after Surgery
Device related adverse events will be collected and reported as the proportion of subjects experiencing them.
Time frame: 6 months after surgery
Plan to share: Yes — De-Identified raw data will be archived at Open Science Framework
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University of North Carolina, Chapel Hill