Children with hearing loss are nearly twice as likely as hearing children to have a diagnosis of autism, and that risk rise with severity of hearing loss. Children with severe to profound hearing loss are more likely to be diagnosed with autism than their peers with more moderate hearing loss. (J Autism Dev Disord 2012;42:2027.)
That does not mean that profound hearing loss causes autism, said lead researcher Christen Szymanski, PhD, the director of research and evaluation at the Laurent Clerc National Deaf Education Center at Gallaudet University in Washington, DC. Dr. Szymanski said no evidence has shown that the social isolation that may occur when a child cannot hear contributes to autism.
Rather, she said she suspects the association is made simply because the two share similar characteristics, such as not responding to one's name, that lead to incorrect diagnoses. The disorders that cause hearing loss also cause autism, predisposing a child with hearing loss to autism, but hearing loss is almost always diagnosed first because of newborn hearing screening.
Most audiologists are likely to be screening, diagnosing, and treating hearing loss in children and adults on the autism spectrum, and they may be able to spot autism signs. Many challenges are involved, however, and many times clinicians trained in hearing loss are not trained in understanding autism or vice versa.
Children with autism are often at risk to have their mild hearing loss missed, said Dr. Szymanski. “That's because often we still rely on sound booth testing of hearing loss. They may struggle to understand when to raise their hand, when to wear the earphones, and how to follow instructions. This may mean that their hearing loss goes undetected.”
Rebecca Davis, AuD, an associate professor of audiology and the interim head of communication sciences and disorders at Southeastern Louisiana University in Hammond, has written for the American Speech, Language and Hearing Association on how best to assess hearing loss in children with autism. “Autism is called a spectrum disorder for a reason,” she said. “There are a wide variety of behavioral challenges and communication problems, and you need to deal with these on an individual basis.”
Dr. Davis recommended following guidelines for assessing hearing in people with autism.
* Plan ahead. If you have a patient with autism coming in, inquire about his needs beforehand. What things distract him? What does he like? How does he respond to unknown circumstances? “It can ruin the assessment in the first minute of interaction if you bring an individual with autism into a room with too much equipment if they typically have fears of that kind of environment,” Dr. Davis said.
* Prepare the patient. You may need to walk a patient with autism through the hearing assessment process on a “practice” basis before going through the real thing. “Take pictures of the booth or make videos for them that a parent can show them ahead of time,” she suggested.
* Minimize distractions. “I pull out anything I don't need to have in the booth,” Dr. Davis said. And if a child with autism is comforted by having a special object in the booth with him, let him bring it in.
* Take small steps. “You might just have to work for a while on getting the patient to accept headphones. When they agree to put the headphones on, they get a reward,” she said.
* Cross-check. Results of any single test should be validated with another independent measure.
Watch for Early Warning Signs
Audiologists can also be looking for early signs of autism spectrum disorders in children with hearing loss, Dr. Szymanski suggested. “For example, a child with correct amplification — be that a cochlear implant or hearing aid — who does have access to spoken language and sound [and] who is not acquiring or producing language should spur the audiologist to look for other red flags,” she said, noting that delayed language acquisition or mastery is a significant characteristic of autism.
Audiologists should be especially vigilant to the nuances of language in their young patients with hearing loss. “Are they using pragmatics [following the rules of conversation] correctly? Are they speaking in the third person?” It is cute when Elmo does it, but when a preschooler or grade-schooler uses the third person saying, “Johnny wants a cookie,” that can be a red flag for autism spectrum disorder.
An audiologist is often the person, other than parents or teachers, who most often sees a child with hearing loss. “They are often on the front lines of recognizing delays in development,” Dr. Szymanski said. She urged every audiologist to become versed in the early warning signs of autism and to be open to recommending that parents take a child for a complete evaluation. The Centers for Disease Control and Prevention's “Learn the Signs” campaign is one helpful tool. “[Audiologists] should also be ready to explain to doctors or other clinicians how the child's hearing loss may impact testing.”
Autism may also be a complicating factor when a child is given cochlear implants, something that should be on audiologists’ radar. “For many children with autism, sound disturbances and texture sensitivities are common,” Dr. Szymanski said. “The cochlear implant may be bothersome for the child. Audiologists need to help recognize this as to not overwhelm the child. Instead of forcing the cochlear implant all at once, more gradual exposure may assure more consistent cochlear implant use later.”
Unfortunately, Dr. Davis noted, a not insignificant proportion of audiologists may avoid working with patients who have autism spectrum disorders, seeing them as too challenging. “But knowing hearing status in these children is just as important as in any child,” she said. “Children with autism need our professional care and expertise and ongoing consideration of their hearing issues.”