Pediatric Hearing Loss – FAQs
- How many children are affected worldwide by hearing loss?
- What should I do if my baby fails the newborn hearing screening?
- Will my child ever hear me?
- Will my child ever talk to me?
- How do I receive special services for my child in my town?
- What should I do if I am worried about my child’s hearing?
- How does the ear work?
- Where does hearing loss occur in the ear?
- How is hearing loss measured?
- Who can test my baby’s hearing?
- What is an audiogram?
- What are the speech frequencies and why are they important?
- What is degree of hearing loss?
- What happens when my hearing-impaired child gets an ear infection?
- How often should my hearing-impaired child’s hearing be tested?
- What are common symptoms of hearing loss in infants?
- Why does my child have hearing loss?
- What is genetic hearing loss?
- Should my child be referred for genetic testing?
- What are the two types of genetic hearing loss?
- What is a syndrome?
- What are the characteristics of nonsyndromic hearing loss?
- What are the characteristics of syndromic hearing loss?
- Are there other types of genetic hearing loss?
- What are some of the diseases that could cause newborn hearing loss?
- What is cytomegalovirus (CMV)?
- What is herpes simplex?
- What is rubella?
- What is varicella (chickenpox)?
- What is syphilis?
- What is toxoplasmosis?
- What is meningitis?
- What are some of the medications used to treat sick children that can cause hearing loss?
- What are some other treatments that can cause hearing loss?
- Why are premature infants at risk for hearing loss?
- Can children with fetal alcohol syndrome have hearing loss?
- What ototoxic medications taken during pregnancy can cause hearing loss in the baby?
- Can lead poisoning cause hearing loss?
- What kind of head trauma might result in a hearing loss?
Hearing loss in children is common with 170 million children with hearing loss worldwide that will need a lifetime of support (WHO, 2002). Hearing loss affects 1 to 3 infants per 1000 births and is the most common congenital sensory disorder. This number increases when conductive hearing losses such as those caused by middle ear problems are included.
If your baby fails his or her initial newborn hearing screening, he or she will most likely be rescreened in the hospital. If your baby fails the hospital rescreen, he or she should have a comprehensive auditory brainstem response (ABR) evaluation. This thorough evaluation will determine the softest sounds at different pitches that your baby responds. If the comprehensive ABR responses are consistent with normal hearing, no further testing is immediately necessary, but some babies’ hearing needs to be monitored for hearing loss that may appear later. If the comprehensive ABR evaluation shows that your baby has hearing loss, you should be referred to an ear physician and for certain cases also a pediatric audiologist to advise you on amplification options.
This depends on the degree of hearing loss. With modern technology, there are very few hearing losses that cannot be helped. For any degree of hearing loss, when appropriate support and technology are given, access to speech sounds and other important sounds is possible.
Speech ability depends on the degree of hearing loss. With appropriate support, most children with hearing loss develop good speech and language and can do almost anything that a person with normal hearing can do. It is critical that the hearing loss be identified early and appropriate intervention begin early to expose your child to speech sounds as early as possible.
All children with special needs living in the United States are eligible for a free, appropriate, public education, from day of diagnosis. Your child may begin receiving assistance from your local education agencies, even as an infant. Contact your local public school district to ask about their programs and services to help you and your child.
If you have any concerns about your child’s hearing, even if your child has already had a hearing test in the past, it is important to seek help as soon as possible. No child is too young to test. Even newborns’ hearing can be tested. The outcomes for many children with hearing loss are better than they have ever been before. Contact us at 972-566-7359 to schedule an appointment to test your child’s hearing.
The ear has three main parts: the outer, middle and inner ear. The outer ear opens into the ear canal. The eardrum separates the ear canal from the middle ear. Small bones in the middle ear help move sound to the inner ear. The inner ear contains the hearing nerve, which leads to the brain. Sounds are vibrations or sound waves in the air that go through the ear canal and hit the eardrum, causing it to vibrate. The vibrations are passed to the small bones of the middle ear, which transmit them to the cochlea and the hearing nerve in the inner ear. The vibrations become nerve impulses that are sent to the brain and are made into meaningful information. The brain is the most important part of the hearing mechanism.
Hearing loss can occur in the outer ear, middle ear, inner ear or brain. Where the hearing loss occurs typically depends on the cause of the hearing loss. An examination and laboratory procedures may also be used to help determine where in the ear the hearing loss occurs.
Sound occurs at different pitches or frequencies and at different loudness levels or intensities. Frequency is measured in Hertz (Hz) and intensity is measured with the decibel (dB). The range of pitches that we hear includes low and high frequencies, ranging from 250 Hz to 8000 Hz. The ranges of intensities that we hear are 0 dB (very soft sound) to 120 dB (very loud sound). A hearing test is a measure of how soft a sound is heard at each frequency.
It is important that you find an audiologist who is experienced with testing hearing of young children. Specialized equipment and techniques are necessary to accurately assess and diagnose a child’s hearing. Our audiologists are experts at these techniques.
An audiogram is a graph that shows the softest level heard at each frequency from 250 Hz to 8000 Hz. Hearing for a child is considered normal at each frequency if it falls above 20 dB on the audiogram.
Speech sounds occur at different frequencies. Most of the vowel sounds occur in the lower frequencies and most of the consonants occur in the higher frequencies. Generally, vowel sounds are louder than consonants. If hearing loss occurs in the high frequencies, it is more difficult or impossible to hear the consonant sounds. The range of frequencies typically referred to as the speech frequencies are 500 to 4000 Hz. The speech frequencies are important because we have to be able to hear speech sounds in order to develop speech and language. If a hearing loss occurs in this range, it interferes with the ability to hear speech, develop speech and language, and to communicate.
The degree of hearing loss refers to the severity of hearing loss. For children, hearing is usually described by the average hearing level (HL) in decibels (dB). For children, a mild hearing loss ranges from 16 dB to 40 dB HL, moderate hearing loss from 41 dB to 55 dB HL, moderately severe hearing loss from 56 to 69 HL, severe hearing loss from 70 dB to 90 dB HL, and profound hearing loss at 91 dB HL or greater.
The presence of middle ear fluid dampens the amount of sound that is transmitted to the inner ear, which causes greater hearing loss, thus, reducing the benefit of your child’s hearing aids. It is important to seek prompt medical attention if an ear infection is suspected.
Children with hearing loss need a hearing test every 3 to 6 months or sooner if concerns arise. Because hearing loss can be progressive, it’s important to closely monitor changes in your child’s hearing. If you suspect your child’s hearing has changed, do not delay seeing your audiologist.
Your baby may have some degree of hearing loss if he or she does not startle, move, cry or react in any way to unexpected loud noises, does not awaken to loud noises, does not turn in the direction of your voice, or does not freely imitate sound.
Sometimes the cause of the hearing loss cannot be determined because there is no known apparent reason for the hearing loss, but in some cases the cause of the hearing loss can be identified. Some common causes of hearing loss are ototoxic drugs, syndromes, heredity, high fevers, complications during pregnancy or childbirth, or certain illnesses.
The “code” that determines the unique characteristics of a person is a gene. Genes determine eye and hair color. A genetic hearing loss is caused by information carried by the genes. Genetic factors make up about 50% of infant hearing loss.
Your physician may refer your child for genetic testing to determine whether your child’s hearing loss is due to non-genetic causes or to a gene that causes hearing loss. This information can inform you of the probability that other children in your family may also have a hearing loss due to the same cause.
The two types of genetic hearing loss are syndromic hearing loss and nonsyndromic hearing loss. About 66% of genetic hearing losses are not related to syndromes and 34% percent are related to syndromes. A nonsyndromic hearing loss means that the hearing loss occurs without involvement of other systems in the body. A syndromic hearing loss means that there is hearing loss in addition to a recognized set of characteristics.
A syndrome is a recognized set of characteristics that occur together. Syndromes are often named after the person that first described it.
Nonsyndromic hearing loss is an inherited pattern of hearing loss that occurs at birth or in early childhood. Connexin 26 is the most common type of nonsyndromic genetic hearing loss. It can be tested by a blood test, but there are many other hearing loss genes that are not as easy to test.
The characteristics of the hearing loss depend on the syndrome. Different syndromes are associated with the different types of hearing loss: conductive, sensorineural or mixed hearing loss. The degree of hearing loss also depends on the type of syndrome. Syndromes are a set of characteristics that affect other parts of the body, most often the eyes, face, head, heart, bones, and kidneys.
Sometimes the ear is not formed correctly. The outside part of the ear can be absent or misshapen. The ear canal can be closed or misshapen. The cochlea might be malformed or misshapen. The hearing nerve can be small or absent. It is not always possible to determine whether these ear anomalies are genetic or not.
Some of the more common diseases associated with hearing loss include cytomegalovirus, herpes simplex, rubella, syphilis, toxoplasmosis, and chickenpox.
CMV is a very common virus. About 3% of babies are born with this virus. Many babies are asymptomatic. Of the small percentage of babies who have symptoms, about 50% are born with hearing loss or develop hearing loss.
Herpes simplex is a virus that is passed from the mother to baby during the delivery. Many of the babies born with herpes develop a combination of neurological problems and hearing loss.
Rubella is a type of measles. If a mother contracts rubella during the first trimester, it can cause heart problems, eye problems and hearing loss. Rubella used to be a common cause of hearing loss, but now with the availability of a vaccine, it is a rare cause of hearing loss.
Varicella also known as chickenpox can cause hearing loss, and skin, eye, bone, and neurological problems if a mother contracts the disease during the first or second trimesters.
Syphilis is a bacterial disease transmitted to the baby during pregnancy. Babies born with syphilis may have teeth, bone, eye, and neurologic problems and hearing loss.
Toxoplasmosis is a parasite infection that is transmitted from mother to baby during pregnancy. The parasite affects the brain, eye, and ears. Babies born with toxoplasmosis are commonly asymptomatic at birth. Hearing loss develops in about 10% of infected babies.
Meningitis is a disease that is contracted after birth. It is an infection or inflammation of the meningis or lining of the brain caused by bacteria or by a virus. Meningitis may result in sensorineural hearing loss. Availability of a vaccine has decreased some types of meningitis.
Some antibiotics that can cause hearing loss include gentamycin, tobromycin, kanamycin and streptomycin. Medications like dopamine or furosemide used to treat oxygen deprivation have also been known to cause hearing loss. Medications for cancer treatment, like cisplatinum, can cause hearing loss.
Jaundice, known as hyperbilirubinemia, is a yellowing of the skin related to elevated bilirubin levels. The treatment for hyperbilirubinemia includes light treatment and may include an exchange transfusion. About 20% of babies treated with exchange transfusion develop hearing loss.
Premature infants and infants with extremely low birth weight sometimes have difficulty breathing normally. This is called persistent pulmonary hypertension (PPHN). The treatment for PPHN may be intubation, ventilation, or oxygen treatment. Hearing loss has been associated with these treatments. Some babies with PPHN may need a treatment called extracorporeal membrane oxygenation (ECMO). Up to 50% of babies with this treatment may develop hearing loss. It is important that these babies receive regular hearing evaluations until they are at least three years of age.
Fetal exposure to alcohol during pregnancy can cause conductive or sensorineural hearing loss. Other features include slow growth development, misshapen facial features, and behavior disorders.
Trimethadione is used to treat seizures and can cause hearing loss if taken by the mother during pregnancy. Other medications known to cause sensorineural hearing loss include acetylsalicylic acid, aminoglycosides, neomycin, nortriptyline, quinine, streptomycin, thalidomide, vancomycin, and viomycin.
Lead poisoning is caused from exposure to paint that is lead based. This type of paint may still exist in some older homes. Babies who eat lead paint chips can get lead poisoning. Lead poisoning causes brain damage and hearing loss.
Trauma is damage or injury that accidentally happens. Infant hearing loss can be caused from head trauma, or other types of ear injuries. Babies born with an enlarged vestibular aqueduct are highly susceptible to head trauma and even a minor head trauma can induce or worsen a permanent hearing loss. Head trauma can cause the bones in the middle ear to be broken apart. Severe head trauma can result in a fracture of the temporal bone causing hearing loss.