Hearing Loss in Adults with Down Syndrome

Overview of hearing loss

Hearing involves several steps as the sound passes from the ear to the brain. The ear is divided into three parts: the outer, middle, and inner ear. Hearing impairment, which is a common problem for adults with Down syndrome (DS) can be associated with any of the three parts of the ear. Hearing loss  is typically divided into three categories: 

• Conductive. This involves impaired transmission from the outer or middle ear to the inner ear. There are many possible causes, including cerumen (ear wax) blocking the ear canal or serous otitis (fluid behind the ear drum). Both conditions seem to be more common in people with DS.

• Sensorineural. This involves the inner ear. Aging and chronic exposure to loud noise are possible causes of this type of hearing loss. In our experience, presbycusis (hearing loss associated with aging) occurs at a younger age in people with DS.

• Mixed. This is a combination of conductive and sensorineural. 

Sometimes, causes are reversible, such as ear wax blocking the canal or fluid behind the ear drum. It can also be due to permanent causes such as inner ear problems or damage. Other problems are not necessarily permanent but can be more challenging to treat. These include perforation in the tympanic membrane (ear drum) or damage to the small bones in the middle ear.

Diagnosis

Hearing problems may be difficult to detect in adults with DS. If the person does not or cannot complain of discomfort in their ears or of their difficulties hearing, behavior changes or skill loss related to hearing loss may be attributed to psychological or other causes. We have evaluated many people who have had a behavioral change or seem to be losing skills in which hearing loss contributed to the symptoms.

Because of the high prevalence of hearing problems in people with DS, we recommend that adults with Down syndrome have their hearing checked every one to two years. Hearing guidelines for children and adolescents with DS can be found in Health Supervision for Children and Adolescents with Down Syndrome (the pediatric medical care guidelines). 

Audiologists are the professionals who assess hearing. An otolaryngologist (ear-nose-throat/ENT doctor) may also be part of the assessment of underlying problems. During a hearing test, sounds are played (typically through headphones but sometimes in a sound booth) and the individual is asked to respond when the sound plays. For those who are unable to do that, alternative testing  is available. 

 

Treatment

Conductive hearing loss may be treated with medications, surgery, and/or removal of cerumen (ear wax) or foreign bodies. A cholesteatoma, a collection of abnormal skin in the middle ear, can damage the small bones in the middle ear and cause conductive hearing loss (and sensory loss if the nerve is affected). Treatment consists of careful cleaning of the ear, antibiotics, and eardrops. Larger cholesteatomas may require surgical removal.

For sensorineural hearing loss, some form of hearing aid may be necessary. Audiologists will typically recommend hearing aids when the hearing loss is significant enough to impair daily function (such as conversational speech). Traditional or typical hearing aids amplify the sound and use the outer and middle ear to transmit amplified sound to the inner ear. While some people with DS find wearing hearing aids very difficult, many can use them successfully.

Bone conduction hearing aids bypass the outer and middle ear and transmit the sound directly to the inner ear bone. A bone conduction hearing aid/implant can be used when a person has a conductive hearing loss (typically that is not correctable by other means); a unilateral (one side only), profound, sensorineural hearing loss; or a mixed hearing loss. The inner ear (cochlea) sensory function is intact, and the device directs the sound through the bone to the cochlea. There are nonsurgical and surgical devices. We found limited research on the use of bone conduction hearing aids in people with DS, and we do not have experience with them. However, we did find a testimonial about the use of a bone anchored hearing aid  in a 10-year-old girl with DS.

A cochlear implant is used for severe bilateral sensory hearing loss that does not respond to hearing aids.  The inner ear (cochlea) sensory function is not functioning in these individuals.   The external device sends the sound signal to the cochlea via the electrode and the signal goes directly to the auditory nerve (and on to the brain).  We have a few patients successfully using a cochlear implant.  There are several reports of successful use of cochlear implants in people with DS:

Cochlear Implants in Eight Children with Down Syndrome  (International Journal of Pediatric Otorhinolaryngology)

Long-Term Outcomes in Down Syndrome Children After Cochlear Implantation  (Otology & Neurotology)

Cochlear Implants Give Boy with Down Syndrome New Lease on Life  (Stanford Medicine)

Having a thorough pre-operative assessment and review by the audiologist and surgeon, following the surgeon’s post-operative recommendations carefully, and following up appropriately with the ENT, audiologist, and speech and language pathologist per their recommendations will likely reduce complications and improve the benefit obtained from a bone conduction hearing aid or a cochlear implant.