What Is Auditory Neuropathy Spectrum Disorder (ANSD)?

The ear gathers sounds from the environment and changes them into messages the brain can understand. But sometimes these messages are jumbled. Other times, the sounds don’t reach the brain. When this happens, it’s called auditory neuropathy spectrum disorder (ANSD).

Kids with ANSD may:

• have trouble telling one sound from another
• not understand speech clearly
• hear sounds that fade in and out
• seem as though their hearing changes

The good news is that kids with ANSD can learn strong language and communication skills with the help of medical devices, therapy, and visual communication techniques.

What Causes ANSD?

Auditory neuropathy spectrum disorder happens when there is damage somewhere along the hearing (auditory) nerve. This is the pathway between the inner ear’s cochlea (which takes sounds and turns them into messages) and the brain.

Children who are born early or have a family member with ANSD are more likely to have it. So are kids who:

• had severe jaundice at birth
• had low oxygen before or after birth
• get some kinds of medicines that may cause damage to the inner ear or hearing nerve
• have genetic or neurologic conditions, such as Charcot Marie Tooth
• had a head injury

What Are the Signs & Symptoms of ANSD?

Symptoms can start at any age, but most kids with ANSD are born with it. Hearing loss can be mild to severe. Some kids hear sounds normally but still have trouble understanding speech clearly.

Even if a child passes a newborn hearing screening, hearing problems might be noticed over time. Talk to the doctor if your child does not reach these hearing milestones in the first year of life:

• For newborns, startling or "jumping" to sudden loud noises.
• By 3 months, recognizing a parent's voice.
• By 6 months, turning the eyes or head toward a new sound and repeating sounds (like “ooh” and “aah”).
• By 12 months, making babbling sounds, responding to their name, imitating words, and saying a few words, such as "mama" or "bye-bye."

As your child gets older, signs of a hearing problem may include:

• limited, unclear, or no speech
• not seeming to pay attention or follow directions
• not responding to conversation-level speech or answering inappropriately
• being easily frustrated when there's a lot of background noise 
• needing a higher TV volume
• learning problems

Talk to your doctor if you have concerns about your child’s hearing.

How Is ANSD Diagnosed?

ANSD is diagnosed by an audiologist. An audiologist specializes in testing and helping people with hearing loss. Hearing tests that can help diagnose ANSD include:

• Otoacoustic emission (OAE): This test measures how well the cochlea works. It's done when the child is lying still or asleep. Tiny earphones are placed in the ear canal. Clicking sounds or tones are made and electrodes (tiny stickers with wires attached) pick up the response from the inner ear (cochlea).
• Auditory brainstem response (ABR): This test measures how well the hearing nerve sends sound from the inner ear to the brainstem (the lower part of the brain). This test can show if the brain is not receiving the information in a clear way. Tiny earphones are placed in the ear canal. Clicking sounds or tones are made and electrodes measure the hearing nerve and brain’s response to the sounds. ANSD is likely when the OAE is normal and there is little or no response during the ABR.
• Middle ear muscle reflex (MEMR) test: Inside the ear is a tiny muscle that tightens when we hear a loud noise. This is called the middle ear muscle reflex (MEMR). For this test, a soft rubber probe tip goes in the ear canal. A series of loud sounds are sent through the tips into the ears. A machine records how well the middle ear muscle reflex reacts to the sounds. In a child with ANSD, loud sounds don't trigger the reflex or sounds need to be louder to trigger it.

Newborn hearing screening programs may use a simple version of OAE and/or the ABR to test a baby's hearing. The complete version of these tests is used to diagnose ANSD.

Children diagnosed with ANSD may need more testing, including: 

• MRI: to look for inner ear problems and to see if there are hearing nerves in both ears
• genetic testing: to see if ANSD is part of a genetic condition
• neurologic testing: to look for any other nerve problems
• vision testing: Hearing and vision problems often go together, so it's important for kids with ANSD to see an eye doctor.

How Is ANSD Treated?

Children with ANSD get care from a team of specialists, such as an audiologist, ear, nose, and throat (ENT) doctor, speech-language therapist, and education specialist. Treatment depends on the child’s age, what part of the hearing nerve is not working, and how much hearing loss there is.

Most kids with ANSD benefit from an assistive listening device. These work best when combined with ongoing speech-language therapy to help improve speaking and hearing skills. Assistive listening devices include:

• Frequency modulation (FM) systems: An FM system helps reduce background noise and makes a speaker's voice louder. The person talking (like a teacher) wears a tiny microphone and a transmitter. The transmitter sends an electrical signal to a wireless receiver that the child wears either on the ear or directly in a hearing aid. It's portable, and can be helpful in classrooms and other loud settings.
• Hearing aid: A hearing aid amplifies sounds coming into the ear. Hearing aids can help some children with ANSD, especially when used with an FM system. Hearing aids used alone do not help kids with ANSD because they only make the disorganized sound louder.
• Cochlear implant: A cochlear implant is an option for some kids with ANSD. This surgically placed device bypasses the parts of the ear that are not working properly. It stimulates the hearing nerve directly. With training and therapy, kids with a cochlear implant can learn to hear and speak well.

What Else Should I Know?

Besides using assistive listening devices, kids with ANSD may learn visual communication skills, such as:

• Sign Language is a special language with a grammar, vocabulary, and syntax all its own. It is meant to be used in place of spoken language.
• Cued Speech is a technique where the speaker makes hand gestures around their mouth. The person watching the speaker uses these hand cues to tell the difference between lip movements that look the same (such as "b" and "p"). Cued speech can be used in any language and can be very useful for bilingual families.
• Signing Exact English (SEE) is a sign system that matches exactly what is spoken in English. It includes sign language, but its sentence structure and grammar are taken from English.

Cued Speech and SEE directly translate what's being said. Both are meant to be used with spoken language to help people understand anything they can't comprehend through lip reading.

Parents play an important role in helping their kids with ANSD learn to communicate by working closely with the care team. You also can find more information and support online at:

• CDC: Hearing Loss and Your Child
  
• Hands and Voices