Published: January 15, 2025

Pearls from Your Peers: Pediatric Single-Sided Deafness (SSD)

The Pediatric Otolaryngology Education Committee interviewed Iram N. Ahmad MD, MME, and A. Eliot Shearer, MD, PhD, about SSD workup and treatment options in children.


Pfyp Feb25

What defines single-sided deafness (SSD), and what are the causes in children?
Single-sided deafness is defined by unilateral severe-to-profound sensorineural hearing loss (SNHL) with a contralateral normal hearing ear. Adults and children with SSD are unable to receive binaural cues that are necessary to localize sound and to better understand speech in noise. The primary cause of SSD is congenital cochlear nerve abnormalities, such as hypoplasia or aplasia. In children who have undergone MRI for workup, approximately 75% of children with true SSD have cochlear nerve deficiency (hypoplasia or aplasia). This means that a child with SSD has a very high likelihood of the deafness being from an absent nerve rather than another etiology. This is important information for treatment decision-making.

What type of workup should be done for SSD in children?
Thinking about a workup based on the timeline, cause and potential treatment options is a useful and comprehensive way to proceed. If the SSD is true congenital SSD as defined above, then imaging is the most useful tool in the workup. Given that studies show that a high proportion of patients with SSD have cochlear nerve deficiency (hypoplasia or aplasia), imaging is recommended as part of the workup. If the patient has SSD that is not congenital and may be due to trauma, sudden sensorineural hearing loss, or infection, then your workup may be altered based on likely etiology.

A patient who experienced head trauma and a temporal bone fracture may need CT and MRI to look for fracture extent, scarring and T2 signal in the cochlea. Infectious causes may require workup with testing for specific infections (e.g., CMV), referral to infectious diseases, etc. This may vary based on the onset of hearing loss. Genetic evaluation is typically not considered in acquired SSD from infection or trauma. 

Do you recommend genetic testing for SSD? How about for unilateral hearing loss that is not SSD? 
Genetic testing using a gene panel has become standard of care in workup for children with bilateral sensorineural hearing loss, as it is the test that is most likely to yield a diagnosis. For this reason, most private insurance now covers genetic testing for this indication. However, given that the majority of SSD in children is due to cochlear nerve hypoplasia or aplasia, genetic testing is less likely to yield a diagnostic result (most research studies show less than 15% diagnostic yield). Insurance is less likely to cover genetic testing for SSD for this reason. Interestingly, recent studies have shown that genetic diagnoses in children with SSD are more likely to include syndromic forms of hearing loss (i.e., hearing loss with associated clinical features like Waardenburg or CHARGE syndrome). More research is clearly needed in this area, but a reasonable current clinical approach is to obtain temporal bone imaging first, and if negative, proceed with genetic testing for SSD.

What treatment options exist for SSD?
Single-sided deafness is an area of hearing loss that has been undertreated, underemphasized and sometimes ignored. Traditional treatment options for children with SSD include observation (“do nothing”), which historically has been favored owing to lack of effective intervention options. In the past, it was thought that children with one normal hearing ear would progress normally and not have significant speech or educational consequences. However, we have learned that children with SSD have a 1/3 higher chance of repeating a grade. They are also at risk for nonauditory deficiencies including low self-esteem, cognitive fatigue, and social difficulties. With this understanding, offering treatment options is critical for the child to have adequate access to sound and avoid these potential deficits.

Treatment options include behavioral interventions, including preferential seating in school, which specifically can mean seating at the front of the classroom with the better hearing ear facing the teacher/instructor. Hearing devices are also part of the treatment. A frequently used device for children in the classroom setting is the frequency modulation (FM) systems that improve the signal-to-noise ratio in environments with high background noise, such as classrooms. Other hearing devices that can be used is the contralateral routine of signal (CROS) device and bone conduction hearing devices (BCHD), both of which route sound to the normal hearing side.

How effective is cochlear implantation for children with single sided deafness?
The above treatment methods do not restore hearing to the affected ear. In 2019, the FDA approved cochlear implantation for children with SSD ages 5 and older. Cochlear implants provide auditory input into the ear with hearing loss, while other devices described above route sound. A cochlear implant is the only device that provides binaural sound and improves localization. However, outcomes are dependent on the patient’s anatomy and the integrity of the cochlear nerve. Cochlear implant outcomes are generally worse for patients with SSD and cochlear nerve hypoplasia, but this is an active area of research. Because of the high prevalence of cochlear nerve deficiency in patients with SSD, and the requirement for a cochlear nerve for cochlear implantation, counseling the families prior to workup is an important aspect of the workup itself.

Additional Resources on SSD in Children and Adults
See also “Pearls from Your Peers: Adult Unilateral Hearing Loss and Single-Sided Deafness,” published in the October 2024 Bulletin. For more on the topic of pediatric SSD, read “Nuances in Pediatric Single-Sided Deafness,” published in the August 2024 Bulletin.



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