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 SSD – 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 SSD 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 SSD are identified, your child’s paediatrician may refer your family to an audiologist who specialises in hearing issues.
An audiologist may perform a type of hearing test called a behavioural 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 SSD.
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 via electrical impulses through an electrode array, which sends the impulses to the auditory nerve.
For SSD patients, 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 SSD.
Some of the major benefits that cochlear implants can offer children with SSD include sound localisation, 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 SSD, helping them to more easily concentrate.
Binaural (two-ear) input of sound to the brain can help with skills like localisation 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 SSD, 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 localisation challenges and tinnitus as they can with cochlear implants.
Cochlear implants are recommended for children living with SSD as young as nine 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 localisation.
Talk with your child’s doctor if you have any concerns about their hearing. – By Diya Kallam and Dr Brian K. Reilly/American Academy of Pediatrics/Tribune News Service
Diya Kallam is a medical student at George Washington University of Medical and Health Sciences in the United States, and Dr Brian K. Reilly is a paediatric otolaryngologist and a member of the American Academy of Pediatrics’ Section on Otolaryngology – Head and Neck Surgery.