“Think about driving your car with the radio on, but you have a frayed wire somewhere between the radio and the speaker system. The sound is entering the perfectly operational radio but is not able to get through the wire and into the speaker in the correct way. Now replace the words radio, wire, and speaker in that sentence with the words cochlea, nerve and brain”
The above is a simple explanation from one mother of a child with Auditory Neuropathy (AN). AN is a less known form of deafness that affects a small percentage of people who are deaf or hard of hearing.
Individuals experiencing AN may have perfect hearing, or a hearing loss ranging from mild to severe. However they always have poor speech perception abilities. They may have trouble recognizing certain words and other times full sentences may seem out of synchronisation.
AN is usually confirmed through a series of tests including an auditory brainstem response (ABR) and a otoacoustic emissions (OAE) test. In this case an atypical ABR reading is found with a normal OAE reading (this indicates the outer hair cells are working normally). These tests are painless and can performed on newborns and older children.
Research has shown that the perception of some newborns improves and they start to hear and speak within a year or two. Unfortunately there is no simple way of telling what their long-term prospects are.
Because the sound gets through a perfectly operating cochlea, hearing aids are often of little help. Due to what could be described as a bad connection between the nerve and the brain the individual experiences sounds, which fade in and out. If the volume in hearing aids is turned up, static is heard, which just gets louder and louder.
Cochlear implants may help. However, as with hearing aids there is no definite research into their benefits to people experiencing AN.
When it comes to education, health professionals suggest that parents work closely with a team of professionals who can advise on educating the child. Parents are encouraged to do all they can to interact with their child by smiling, holding, facing the child and responding to communication.
One option is sign language while another is to use listening and spoken skills with hearing devices or implants. A combination of these approaches is also favoured. Older children and adults who have already been speaking and understanding speech are encouraged to learn how to lipread.
(compiled by Miriam Walsh)