Hearing Loss Infants
An infant or baby is the very young offspring of human beings. Infant (from the Latin word infans, meaning baby or child) is a formal or specialised synonym for the common term baby. The terms may also be used to refer to juveniles of other organisms. A newborn is, in colloquial use, an infant who is only hours, days, or up to one month old. In medical contexts, a newborn or neonate (from Latin, neonatus, newborn) is an infant in the first 28 days after birth; the term applies to premature, full term, and postmature infants.
Infants born prior to 37 weeks of gestation are called premature, those born between 39 and 40 weeks are full term, those born through 41 weeks are late term, and anything beyond 42 weeks is considered post term.
Before birth, the offspring is called a fetus. The term infant is typically applied to very young children under one year of age; however, definitions may vary and may include children up to two years of age. When a human child learns to walk, they are called a toddler instead.
What is hearing loss?
Hearing loss can happen when any part of the ear isn’t working in the usual way. It can range from mild to profound:
- Mild: You can hear some speech sounds, but soft sounds are hard to hear.
- Moderate: You can’t hear very many speech sounds when someone is talking at a normal level.
- Severe: You can’t hear any speech sounds when someone is talking at a normal level. You can only hear some loud sounds.
- Profound: You can’t hear any speech sounds. You can only hear very loud sounds.
Hearing loss is a common birth defect. Birth defects are structural changes present at birth that can affect almost any part of the body. They may affect how the body looks, works or both. Birth defects can cause problems in overall health, how the body develops, or how the body works. Up to 3 in 1,000 babies (less than 1 percent) are born with some kind of hearing loss in the United States each year.
When a baby is born with hearing loss, it’s called congenital hearing loss. Hearing loss also can develop later in babies or during childhood or adulthood.
What are signs of hearing loss?
Signs of hearing loss in your baby can include:
- Not being startled by loud sounds
- Not turning toward a sound after he’s 6 months old
- Not saying single words like “mama” or “dada” by the time he’s 1 year old
- Turns his head if he sees you, but not if you only call out his name
- Seems to hear some sounds but not others
If your baby shows signs of hearing loss at any time, call his health care provider to get your baby’s hearing checked.
What are common types of hearing loss?
Your baby’s auditory system is the system in the body that helps her hear. It makes sense of sound information as it travels from the ear to the brain. Problems in these parts of the auditory system may cause hearing loss:
- Outer ear. This includes the part of the ear on the outside of the head, the ear canal and the outside of the eardrum. The eardrum separates the outer and middle ear.
- Middle ear. This is made up of the inside of the eardrum and three small bones called ossicles. Sound coming into the ear moves through the ear canal to the eardrum, causing the eardrum to vibrate (move back and forth quickly). When the eardrum vibrates, it moves the ossicles. This helps sound move to the inner ear.
- Inner ear. This is made up of the cochlea (a curled tube filled with fluid) and canals that help with balance. The inner ear also has nerves that change sound vibrations into signals that travel to the brain through the auditory nerve (also called the hearing nerve). The auditory nerve sends sound information from the ear to the brain.
Common types of hearing loss include:
- Conductive hearing loss. This happens when there’s a problem in the outer or middle ear that slows or prevents sound waves from passing through. Problems may include a blockage in the ear canal or fluid in the middle ear. This kind of hearing loss often is temporary and usually can be treated with medicine or surgery.
- Sensorineural hearing loss. This happens when there’s a problem with the way the inner ear or auditory nerve works. It may happen when certain cells in the inner ear are damaged. This kind of hearing loss is usually permanent.
- Mixed hearing loss. This when a baby has both conductive and sensorineural hearing loss.
- Auditory neuropathy spectrum disorder (also called ANSD). In this condition, a problem with the inner ear or auditory nerve prevents the brain from understanding sound.
How can hearing loss affect your baby?
Early screening, diagnosis and treatment can help children with hearing loss develop speech, language and social skills. Without early treatment, hearing loss can lead to:
- Delayed or limited language and speech development. For example, babies and children with hearing loss may have trouble understanding things that other people say, learning new words and saying words the right way. Children with untreated hearing loss may have poor communication skills.
- Learning and social problems. Without early treatment, children with hearing loss may have problems learning in school. Hearing loss also may make it hard for them to be social with other children.
Causes
Although it is not common, some infants may have some hearing loss at birth. Hearing loss can also develop in children who had normal hearing as infants.
- The loss can occur in one or both ears. It may be mild, moderate, severe, or profound. Profound hearing loss is what most people call deafness.
- Sometimes, hearing loss gets worse over time. Other times, it stays stable and does not get worse.
Risk factors for infant hearing loss include:
- Family history of hearing loss
- Low birth weight
Hearing loss may occur when there is a problem in the outer or middle ear. These problems may slow or prevent sound waves from passing through. They include:
- Birth defects that cause changes in the structure of the ear canal or middle ear
- Buildup of ear wax
- Buildup of fluid behind the eardrum
- Injury to or rupture of the eardrum
- Objects stuck in the ear canal
- Scar on the eardrum from many infections
Another type of hearing loss is due to a problem with the inner ear. It may occur when the tiny hair cells (nerve endings) that move sound through the ear are damaged. This type of hearing loss can be caused by:
- Exposure to certain toxic chemicals or medicines while in the womb or after birth
- Genetic disorders
- Infections the mother passes to her baby in the womb (such as toxoplasmosis, measles, or herpes)
- Infections that can damage the brain after birth, such as meningitis or measles
- Problems with the structure of the inner ear
- Tumors
Central hearing loss results from damage to the auditory nerve itself, or the brain pathways that lead to the nerve. Central hearing loss is rare in infants and children.
Symptoms
Signs of hearing loss in infants vary by age. For example:
- A newborn baby with hearing loss may not startle when there is a loud noise nearby.
- Older infants, who should respond to familiar voices, may show no reaction when spoken to.
- Children should be using single words by 15 months, and simple 2-word sentences by age 2. If they do not reach these milestones, the cause may be hearing loss.
Some children may not be diagnosed with hearing loss until they are in school. This is true even if they were born with hearing loss. Inattention and falling behind in class work may be signs of undiagnosed hearing loss.
How is hearing loss treated?
Treatment depends on your baby’s overall health and the cause of the hearing loss. If your baby has hearing loss, it’s important to start treatment as soon as possible and before she’s 6 months old. This can help her develop speech, language and social skills. Treatment may include:
1.Cochlear implant. This is a small electronic device that can help some babies with severe or profound hearing loss. One part of the implant sits on the head behind the ear. The other parts are placed inside the ear during surgery. The part behind the ear sends sounds to the parts inside the ear. Babies as young as 1 year old may get a cochlear implant. It doesn’t give a baby complete hearing, but it can give a baby a sense of sound. Hearing through a cochlear implant is different from normal hearing. Specialists, like audiologists and speech therapists, can help your baby learn to hear through the implant and develop her speech, language and social skills.
2.Ear tubes. These are tiny tubes placed through the eardrum. Ear tubes allow air into the middle ear and prevent fluids from building up behind the eardrum. Your child may need ear tubes if:
- She gets a lot of ear infections (about three or more in 6 months or four or more in 1 year)
- She has fluid buildup and inflammation (redness and swelling) behind the eardrum
- If she has hearing loss due to ear infections
3. Hearing aid. Hearing aids make sounds louder. Hearing aids can help babies as young as 1 month old. If your baby has severe or profound hearing loss, a hearing aid may not help.
4. Learning special language skills. Children with hearing loss may need special language skills to communicate with others. For example, some may learn American Sign Language (also called ASL) to communicate. ASL uses the shape, placement and movement of hands, along with facial expressions and body movement, to communicate.
5. Medicines, including antibiotics. If your child has an ear infection that causes hearing loss, her health care provider may prescribe an antibiotic like amoxicillin. Her provider also may suggest over-the-counter (also called OTC) medicines to help with fever and pain. These medicines may include ear drops, acetaminophen (brand name Tylenol®) and ibuprofen (brand names Motrin® or Advil ®).
6. Speech therapy. This is therapy to teach your child how to speak more clearly or communicate in other ways. Speech-language pathologists (also called speech therapists) are professionals who can help children learn how to make sounds, improve their voices and interact with others.
7. Surgery. Surgery can sometimes correct problems with the structure of the outer and middle ears.
After birth
Take your baby to all his well-baby checkups. At these checkups, your baby’s provider checks your baby’s overall health, growth and development. Your baby also gets vaccinations to help protect her from harmful infections.
Get early treatment for ear infections. If you think your baby has an ear infection, call his provider right away. Signs and symptoms of ear infection include:
- Tugging on ears
- Having trouble hearing or sleeping
- Crying more than usual, especially when your baby is lying down
- Having balance problems
- Fever
- Headache
- Fluid coming out of the ears
Keep your baby away from loud sounds. Close windows and doors in your home to limit loud sounds near your baby. Keep TV and radio volumes low. Give your baby quiet toys or toys with volume control set to the lowest volume. Don’t take your baby to noisy events, like concerts or fireworks shows. If you do take your baby to a loud place, use earplugs or earmuffs to limit noise. If your baby is covering his ears or looks uneasy in a noisy place, it’s probably best to leave.
Exams and Tests
Hearing loss makes a baby unable to hear sounds below a certain level. A baby with normal hearing will hear sounds below that level.
The health care provider will examine your child. The exam may show bone problems or signs of genetic changes that may cause hearing loss.
The provider will use an instrument called an otoscope to see inside your child’s ear canal. This allows the provider to see the eardrum and find problems that may cause hearing loss.
Two common tests are used to screen newborn infants for hearing loss:
- Auditory brain stem response (ABR) test. This test uses patches, called electrodes, to see how the auditory nerve reacts to sound.
- Otoacoustic emissions (OAE) test. Microphones placed into the baby’s ears detect nearby sounds. The sounds should echo in the ear canal. If there is no echo, it is a sign of hearing loss.
Older babies and young children can be taught to respond to sounds through play. These tests, known as visual response audiometry and play audiometry, can better determine the child’s range of hearing
Treatment
Over 30 states in the United States require newborn hearing screenings. Treating hearing loss early can allow many infants to develop normal language skills without delay. In infants born with hearing loss, treatments should start as early as age 6 months.
Treatment depends on the baby’s overall health and the cause of hearing loss. Treatment may include:
- Speech therapy
- Learning sign language
- Cochlear implant (for those with profound sensorineural hearing loss)
Treating the cause of hearing loss may include:
- Medicines for infections
- Ear tubes for repeated ear infections
- Surgery to correct structural problems
Signs of hearing loss in infants vary by age. For example: A newborn baby with hearing loss may not startle when there is a loud noise nearby. Older infants, who should respond to familiar voices, may show no reaction when spoken to. Some children may not be diagnosed with hearing loss until they are in school. This is true even if they were born with hearing loss. Inattention and falling behind in class work may be signs of undiagnosed hearing loss.
Hearing loss can run in families. Your baby’s doctor will monitor your little one’s hearing closely. If there is a hearing problem, treatment should begin as soon as possible.
In most states, newborns get a hearing screening before going home. If it’s not done then, or a baby was born at home or a birthing center, it’s important to check their hearing within the first 3 weeks of life.
A baby who doesn’t pass a hearing screen doesn’t necessarily have a hearing loss. A repeat hearing test should be done by 3 months of age. If it confirms a hearing problem, doctors recommend starting treatment before 6 months.
Even newborns who pass their initial hearing screening should be watched for signs that they might not be hearing well. Children with hearing loss won’t respond to sounds or their language development may be slow.
Hearing milestones in the first year of life include:
- Most newborns startle or “jump” to sudden loud noises.
- By 3 months, a baby recognizes and calms to a parent’s voice.
- By 6 months, babies turn their eyes or head toward a new sound and repeat sounds.
- By 12 months, babies make babbling sounds, responds to their name, imitate words, and may say a few words, such as “Mama” or “bye-bye.”
