Hearing Loss | Symptoms & Causes
What are the symptoms of hearing loss?
Newborns and infants respond to sounds long before they can communicate through speech. If a baby has hearing loss, they may:
- not get startled or upset by sudden loud noises
- not recognize their parents’ voices by the age of 3 months
- not turn their head toward a sound by the age of 6 months
- not imitate sounds or simple words by the age of 12 months
In toddlers and older children, hearing loss symptoms include:
- delayed language skills
- abnormal speech
- insistence on listening to television or music at a high volume
- learning difficulties
- not paying attention to conversations
- not responding when someone calls their name
- trouble hearing over background noise
What causes conductive hearing loss?
With conductive hearing loss, a problem in the outer or middle ear blocks the passage to the inner ear. Ear infections that cause fluid to build up in the ear are the most common cause of conductive hearing loss and can typically be treated with medication.
Other causes include:
- colds or allergies that cause fluid to build up in the ear
- small objects that become stuck in the ear
- excessive ear wax in the ear canal
- non-cancerous tumors that block the ear canal
- congenital deformities of the outer or middle ear
What causes sensorineural hearing loss?
Sensorineural hearing loss is a problem with the inner ear. Typically, hair cells in the inner ear convert signals from the middle ear into electrical signals which are sent to the brain and interpreted as speech or sound. A child has sensorineural hearing loss when the hair cells in the inner ear are damaged.
Sensorineural hearing loss is sometimes present at birth while for other children, it develops later. This is considered acquired hearing loss.
Causes for sensorineural hearing loss at birth include:
- genetics: children of parents with hearing loss are more likely to have hearing issues as well
- premature birth
- low birth weight
- mother infected with toxoplasmosis, rubella, cytomegalovirus, herpes, or syphilis during pregnancy
Causes of acquired sensorineural hearing loss include:
- exposure to loud noises
- head trauma
- infection
- being on a ventilator for a long time
- having congenital diaphragmatic hernia or needing extracorporeal membrane oxygenation (ECMO) therapy
- repeated courses of IV antibiotics and diuretics
Hearing Loss | Diagnosis & Treatments
How is hearing loss diagnosed?
Screening for hearing loss is a staple of pediatric care. Babies born in U.S. hospitals are screened for hearing loss within their first month of life. Toddlers and children should continue to be screened for hearing loss at regular intervals through the age of 10, and more often if they show signs of hearing loss.
If your child shows signs of hearing loss, their doctor may refer them to an ear doctor, known as an audiologist, for further testing. The type of hearing test will depend on your child’s age.
What are the treatment options for hearing loss?
Some hearing problems are medically or surgically correctable. Other hearing problems are treated with hearing aids and speech and language therapy.
The three most common types of treatment are:
- Use of hearing aids: These electronic or battery-operated devices can amplify and change sound. A microphone receives the sound and converts it into sound waves. Then, the sound waves are converted into electrical signals.
- Cochlear implant: This is a surgically placed appliance that helps to transmit electrical stimulation to the inner ear. Only certain children are candidates for this type of device. Ask your child's physician for more information.
- Training in ASL and lip reading
How is conductive hearing loss treated?
Conductive hearing loss is usually temporary. Treatment depends on how it was caused. If a foreign object is blocking the ear, a clinician will take steps to remove it. Parents should be very careful not to push the object further into the ear with a Q-tip or other tool. If a clinician sees excessive ear wax in the ear canal, they may use a special tool to remove it. This only takes a few minutes.
Other possible treatments include:
- Medication: Antibiotic or antifungal cream is often used to treat hearing loss caused by recurring ear infections.
- Ear tubes: Small tubes are surgically placed in the child’s eardrum to drain fluid out of the middle ear and reduce the risk of ear infections.
- Surgery: A clinician may recommend surgery to treat hearing loss caused by head trauma or a malformed ear or ear canal.
How is sensorineural hearing loss treated?
Sensorineural hearing loss is usually permanent. Because hearing is central to a child’s ability to develop language skills, it is important to seek treatment as soon as possible.
Early intervention helps children with hearing loss develop language skills using a combination of reading, speaking, lip reading, sign language, and other tools. It can also teach parents skills to help them communicate with their child effectively.
Early intervention is most effective when started early. The Centers for Disease Control and Prevention recommend that babies with hearing loss start receiving intervention services as soon as possible, no later than 6 months of age. The earlier a child with hearing loss starts learning speech, language and social skills, the better.
Hearing aids are electronic or battery-operated devices that amplify sound. For many children with mild or moderate hearing loss, a hearing aid can produce almost normal clarity of speech in a quiet room. Children with severe or profound hearing loss will be able to pick up some sounds through a hearing aid but typically need to combine lip-reading or sign language to understand speech and participate in conversations fully.
Cochlear implants are electronic devices that partially restore hearing for children with severe or profound hearing loss in both ears. Instead of transmitting sound through the ear like a hearing aid, a cochlear implant picks up sounds through a speech processor worn behind the ear and transmits it to a hearing device implanted in the inner ear. This helps children hear many sounds, including speech, but will not restore normal hearing. With consistent “listening” therapy and practice, children with cochlear implants can often learn to understand spoken language.
How we care for hearing loss
Our clinicians in the Department of Otolaryngology and Communication Enhancement at Boston Children's Hospital have extensive expertise evaluating and treating hearing loss. Our Hearing Disorders Clinic and Audiology Program offer comprehensive, multi-disciplinary evaluation and management of various degrees of hearing loss in infants, children, and adolescents. We work closely with specialists in Boston Children’s Deaf and Hard of Hearing Program, one of the largest, most comprehensive hearing-loss programs in the country, to provide comprehensive evaluation and consultative services for children who are deaf or hard of hearing.
