Auditory Neuropathy Spectrum Disorder

A newborn hearing screening can often catch signs of ANSD. Otherwise, symptoms may not be obvious, or they may only appear over time. Symptoms can vary from mild to severe and are not predictable – they can vary from person to person and change over time. Common symptoms of ANSD include:

• Hearing loss
• Changes in hearing – even on a day to day basis
• Difficulty understanding speech in loud settings or speech that changes quickly
• Difficulty distinguishing sounds
• Can’t tell the difference between sounds
• Sounds may seem distorted or different than expected
• Delayed speech ability based on age

As your baby develops, watch for signs of hearing loss. Talk to a pediatrician if your baby:

• Does not startle or react to loud noises
• Does not wake to loud sounds, especially if sleeping in a quiet place
• Is not calmed by your voice or soft sounds
• Does not turn their head towards noises and sounds (by 3 months)
• Does not show interest with “noisy” toys, like rattles
• Does not make certain vocal sounds:
• By 2 months, is not cooing
• By 6 months, is not making vowel sounds (ooh, aah)
• By 8 months, is not babbling or laughing
• By 12 months, is not trying to imitate sounds, making consonant sounds, or saying simple words (mama, dada)

Check with your doctor if your child has any of the symptoms listed above.

The exact cause of ANSD is not known.

For some, the disorder is caused by genetic factors. This means ANSD can be hereditary or passed from parents to child – even if the parents don’t have signs of the disorder.

Many other risk factors are related to problems with pregnancy and birth, including:

• Head injury (trauma).
• Illness. Severe cases of jaundice can cause lasting damage to the inner ear and brain.
• Infection. Bacterial meningitis is a common cause of deafness in children. Other types of infections can be passed to the baby before birth (congenital), during birth (perinatal), or after birth (neonatal) and can impact hearing.
• Lack of oxygen (anoxia [an-OK-see-uh] or hypoxia [hi-POK-see-uh]).
• Medicines. Certain medicines, including those used to treat some infections, can cause hearing loss in newborns and infants. These types of medicines are known as ototoxic [oh-tuh-TOK-sik.
• Premature birth and low birth weight. The lower the the number of weeks pregnant (gestational age) and the lower the birth weight, the greater the risk.

In older children (ages 6-19), constant exposure to loud noises is a cause of damage to the inner ear and auditory (hearing) system, especially at higher frequencies (high pitched noises). This particular cause has become more common in recent years due to increased use of portable media devices and headphones.

Two tests are commonly used to screen for hearing problems in both newborn babies and older children: the otoacoustic emissions (OAE) test and the auditory brainstem response (ABR) test. Both screening tests are painless and take 15 to 45 minutes. Many babies sleep through the hearing screenings.

While these tests can detect signs of ASND and hearing loss, they can’t diagnose the severity of the disorder. Additional testing will be needed as the child grows older. It is also possible for a child to pass these tests and still have or develop ASND. Talk with your baby’s doctor if you notice any symptoms of hearing loss (see above).

There are no cures for ANSD. However, there are ways to help manage the disorder. Treatment options will often depend on age, cause, and severity of hearing loss. Treatment generally focuses on improving hearing (if possible) with assisted listening devices and finding alternate ways to communicate.

Assisted listening devices. Some children benefit from the use of assisted listening devices, such as hearing aids, cochlear implants, and frequency modulation (FM) systems. Your audiologist will help you decide which devices to consider.

Communication skills. Your child may need special help to learn to communicate. This may involve speech-language therapy, or it may require learning visual communication techniques, such as sign language.

In most cases, there is no way to prevent ANSD.

In older children, consider using volume-limiting headphones to decrease the risk of noise-induced hearing loss.

• Intermountain Fact Sheet: Newborn Hearing Screening
• The National Institute on Deafness and Other Communication Disorders (NIDCD):
• KidsHealth
• Utah Department of Health
• Centers for Disease Control and Prevention

Auditory Neuropathy Spectrum Disorder (ANSD) is a hearing disorder that affects how the brain receives sounds from the ears. In order to hear sounds, the ear must change sound vibrations into tiny electrical signals that the brain can use. This process happens in the cochlea, which is found in the inner ear. The cochlea contains thousands of sensitive hair cells that move when reached by sound waves. As the hairs move, they trigger nerve impulses (electrical signals) that are sent to the brain through a special hearing nerve. The brain then interprets these signals as sounds.

Often with ANSD, the outer and middle parts of the ears work normally. Problems in the inner ear (cochlea) or with the hearing (auditory) nerve can cause the sound signals to become distorted before they reach the brain. This distortion can make it hard for people to hear, identify, or understand sounds, especially speech. For some, the disorder may cause total hearing loss (deafness).

ANSD can affect people of all ages. However, in babies and young children, ANSD creates specials challenges. Good hearing is important for a baby’s learning and speech development. Most babies don’t have hearing loss. But if your baby does have a hearing problem, it’s important to catch it early. A baby is constantly learning during the first months and years of life. If you learn early on that hearing loss is present, your baby can get early treatment. This will give your baby the best chance to develop normal language, social, and learning skills.

If your baby is diagnosed with hearing loss, you will be referred to a pediatric audiologist – a doctor who specializes in hearing in babies and children. The doctor will do additional testing and may recommend the use of assisted listening devices, such as hearing aids or cochlear implants.

You will also be referred to an early intervention program. These are free programs established under the Individuals with Disabilities Act 2004. The programs help parents understand hearing loss, get support, and create a plan to help children learn and develop.