Can hearing problems contribute to autism-related language delays?

This answer is by audiologist Susan Eichert of the Autism Speaks Autism Treatment Network center at Cincinnati Children’s Hospital Medical Center.

Our child has autism, and we’re wondering whether hearing problems may be contributing to his lack of language. Will an ordinary hearing test work for him? Who should we see and what can we do?

Your concerns around your son’s language delay are well founded. Hearing problems can indeed contribute to language delays and often do so. In fact, any degree of hearing loss can hamper a child’s communication and learning success. So a thorough hearing evaluation is important for any child with delayed speech or language skills.

Chances are your son had a hearing screening around the time of his birth. The results may have been perfectly normal. But hearing can change over time.

Among young children, hearing loss commonly involves otitis media, or a build-up of middle-ear fluid. This may or may not be associated with an active ear infection. In fact, otitis media is the single, most-common reason for sick-child doctor visits in the United States and Canada. As many as 75 percent of children have at least one ear infection by age three. Nearly half of these have three or more ear infections by age three. These infections often lead to a buildup of fluid in the middle ear. This can interfere with hearing – sometimes long after the obvious infection has cleared.

Hearing tests for children with developmental delays

A pediatric audiologist is the best professional to assess hearing sensitivity. I think this level of expertise is particularly important for assessing hearing in children who have developmental delays. You can find a pediatric audiologist in your area using the searchable directory on the Early Hearing Detection & Intervention website. If you live near an Autism Speaks ATN center, this would be an excellent place to find an audiologist experienced in working with children affected by autism. Find the ATN nearest you.

There are two basic types of audiology testing: objective and behavioral. Each has merits and drawbacks for testing children who have a developmental disorder such as autism. That your son is nonverbal – in and of itself – should not interfere with his taking any of these tests. But some approaches may be more appropriate than others depending on his level of behavioral development.

Behavioral hearing tests

In behavioral testing, the audiologist asks the child to respond when he or she hears a test sound. For example, “Raise your hand when you hear the beep.” (See image at right.) This works best for children who have a developmental level of at least 5 or 6 years old.

For children at a preschool level, we often adapt this behavioral approach to include an element of play. For example, we might ask the child to throw a ball in a basket or put money in a piggy bank when he or she hears the test sound.

Typically, we perform hearing tests with the child wearing headphones. For children who won’t tolerate headphones, we can do the test using sound speakers.

We have yet another approach when testing the hearing of children whose developmental level is under 2.5 years of age. In visual reinforcement audiometry, the child sits on the parent’s lap in the middle of a quiet sound booth with speakers on either side. We play sounds through the speakers. When the child looks toward a sound, we “reward” the response with an animated toy or video display.

All these tests allow us to observe whether a child hears a tone by gauging his or her behavioral reaction to it. I find visual reinforcement audiometry particularly effective for children affected by autism – regardless of age. This may be because it doesn’t require social interaction.

One of the greatest satisfactions in my work is helping children succeed in the sound booth no matter their developmental level. Parents are often surprised about how much information their child can offer without speaking a single word.

Objective hearing tests

Yet there are times when behavioral hearing tests present too great a sensory challenge for a child who has autism. This is when we consider the option of an objective hearing test. Examples include the otoacoustic emissions test, tympanometry and auditory brainstem response.

Tympanometry allows us to quickly check for middle-ear fluid that may be interfering with hearing. However, it’s not a hearing test per se. The audiologist places a soft, plastic tip on the outer edge of the child’s ear. The device delivers a quiet tone along with a gentle change of air pressure to determine how the eardrum moves in response to the pressure.

An oto-acoustic emissions test takes around 3 to 5 minutes. The audiologist places a small, soft sponge on the edge of the child’s ear canal. Through this, the device delivers a series of quiet sounds. A normal ear will “echo” the sounds back to the device. This allows us to determine whether hearing is essentially normal. If not, we would continue to auditory brainstem testing to determine what type of hearing loss the child has. 

In an auditory brainstem response test, the audiologist places adhesive electrodes on the child’s forehead and behind the ears. The electrodes record electrical brain activity in response to test sounds played through headphones. This test takes about 20 to 30 minutes on a sleeping child. 

None of these tests require a behavioral response from the child. However, they do require that the child remains quiet and still for 5 to 30 minutes. Frequently this means that we need to sedate the child.

Sedation is never a first choice. What’s more, we know that most of the children we are testing will have normal hearing results. However, it’s critical for us to answer the question of whether some degree of hearing impairment is contributing to a child’s speech and language delays. This is the first step to addressing any hearing problem and, in doing so, opening up a whole new world for your child.