What is Auditory Neuropathy Spectrum Disorder (ANSD)?
ANSD is a hearing disorder in which sound enters the ear normally but the signal from the ear to the brain is impaired. ANSD can affect people of all ages. The number of people with ANSD is not known. Some children with ANSD have normal hearing; others have hearing loss that ranges from mild to profound. Children with ANSD have difficulty understanding speech clearly. A child’s ability to understand speech is worse than would be predicted by the degree of hearing loss. This means a child may be able to hear sounds but has a hard time recognizing spoken words. There may be days when the child seems to hear better than others.
What causes ANSD?
We do not fully understand what causes ANSD. The cause may be damage to the hair cells in the ear canal, a poor connection to the hearing nerve that leads to the brain, or damage to the hearing nerve.
Factors that put a child at risk for ANSD
- Premature birth
- Low birth weight
- Artificial ventilation
- Genetic conditions
- Neurological disorders
- Cochlear nerve deficiency
Symptoms of ANSD
Children with ANSD have a difficult time recognizing words. They have a hard time hearing in noisy situations. Hearing may be better one day and worse the next and the child may have “good listening days” and “bad listening days.”
An audiologist will diagnose ANSD. They will do an Auditory Brainstem Response (ABR) test and an otoacoustic emission (OAE) test on your child. Depending on your child’s age they may need other tests. During the ABR test, small microphones are placed in the ears and electrodes placed on your child’s head measure brain activity while your child is listening to sound.
Can ANSD improve over time?
We do not know if ANSD can and/or will improve over time. Some people’s symptoms seem to improve over time. If the condition is going to improve it usually improves in the first few years of life. As we do not know if your child’s ANSD will improve it is important to have follow up and testing as your doctor suggests.
How is ANSD treated/managed?
Your child care team will include parents, an audiologist, a speech-language pathologist, an Ear Nose and Throat doctor, and the education team. Treatment depends on how severe the ANDS is and the age it is diagnosed. While there is no cure for ANSD there are some listening devices that may help.
- Hearing Aid: A hearing aid makes sounds that enter the ear louder. Not all children will benefit from wearing a hearing aid. Because a hearing aid may help it is important to consider as a treatment option.
- Cochlear Implant (CI): A cochlear implant is an electronic device that provides the sense of sound to a person. A small transmitter sits behind the ear and an internal unit is surgically implanted inside the head in the cochlea. A child with a CI will need speech therapy to learn to hear and speak well. Cochlear implants combined with speech therapy have helped many children with ANSD. Not all children with ANSD will be candidates for cochlear implantation.
- Frequency Modulation (FM) System: A FM system reduces background noise and makes a speaker’s voice louder. This helps the child to better understand the speaker. The speaker wears a microphone and a transmitter that sends an electronic signal to the FM receiver worn by the child. It can be useful at school and at home.
The best way to communicate with children with ANSD
Some children will benefit from learning to listen and speak. Others will benefit more from learning sign language. Other children may use a combination of both. Making a communication choice can be a difficult decision. All families have different circumstances that affect the decision they make. What is right for one family may not be right for another. It is important that no matter what option is chosen the child is evaluated over time to see how well it is working. Professionals from the team can help families decide whether or not a certain approach is working.