Single-sided deafness (SSD) is a hearing impairment that affects at least one in every 1,000 babies born. These infants have severe-to-profound hearing loss in one ear with normal or near-normal hearing in the other ear. The condition can also develop in older children and adults.
If your child shows symptoms of single-sided deafness, sometimes called unilateral hearing loss, talk with their doctor right away. Hearing impairment can make it difficult for children to learn languages and speech. But prompt treatment can help avoid problems.
Symptoms of single-sided deafness to know:
— Tinnitus (ringing) in one ear
— Selective use of phone in only the hearing ear
— Head turning to hear the source of a sound
— Difficulty hearing in noisy environments
— Auditory fatigue from the extra effort that listening requires with hearing impairment
Early diagnosis and treatment for hearing impairment is key.
If any symptoms of single-sided deafness are identified, your child's pediatrician may refer your family to an audiologist who specializes in hearing issues. An audiologist may perform a type of hearing test called a behavioral audiogram. For infants, an audiologist will perform an auditory brainstem response test. This hearing test involves tonal sounds and clicks that are played. Electrodes measure your child's response to the noises by tracking brainwaves.
Once diagnosed, there are several treatment options for single-sided deafness. Treatment may include steroids, varied seating in the classroom, hearing aids or bone conduction hearing devices. The most successful treatment for SSD is cochlear implantation.
A cochlear implant is an electronic device that sends signals to the cochlea (inner ear). These signals are perceived as sound and coded into speech.
A cochlear implant consists of four parts: a microphone, sound processor, transmitter and electrode array. The microphone picks up sounds which are converted by the sound processor. The transmitter then sends the sounds into electrical impulses through an electrode array, which takes the impulses to the auditory nerve.
For patients with single-sided deafness, the cochlear implant is placed surgically under the scalp and behind one ear. Cochlear implants have been shown to improve hearing over time and offer a better quality of life for children with single-sided deafness.
Some of the major benefits that cochlear implants can offer children with SSD include sound localization, or the ability to identify the origin of a sound. Another is improvement in speech discrimination, which is the ability to hear speech in quiet and noisy environments. Tinnitus reduction can be a major benefit for children with single-sided deafness, helping them to more easily concentrate. Binaural (two-ear) input of sound to the brain can help with skills like localization and speech discrimination. Cochlear implants allow for binaural input, which can increase listening attention span.
Although there are risks to cochlear implantation surgery, complications are rare and almost all patients recover quickly from them.
There are alternate treatments for single-sided deafness, including contralateral routing of sound devices, osseointegrated implants and bone anchored hearing aids.These technologies can improve speech discrimination, although research shows that the devices are not as successful as cochlear implants. Patients are not able to overcome localization challenges and tinnitus as they can with cochlear implants.
Cochlear implants are recommended for children living with single-sided deafness as young as 9 months old. Earlier implantation typically results in better speech and language outcomes. Young children who receive cochlear implants typically show improvement in sound discrimination, speech development and sound localization.
Talk with your child's doctor if you have any concerns about their hearing.
More information is available at HealthyChildren.org.
———
ABOUT THE WRITERS
Brian K. Reilly, MD, FACS, FAAP, is a pediatric otolaryngolist and a member of the American Academy of Pediatrics Section on Otolaryngology – Head and Neck Surgery. He is co-director of the Cochlear Implant Team at Children's National Hospital.
Diya Kallam is a medical student at George Washington University of Medical and Health Sciences.
