As they research their child’s disability, many parents learn about sensory integration and the importance of the body’s vestibular system, perhaps the most basic of all the sensory systems. Initially they learn that the vestibular system coordinates body movements, maintains balance and equilibrium, and helps children develop normal muscle tone. It is not as immediately apparent, though, how the vestibular system influences auditory-language processing. However, the vestibular system plays a significant role in the development of language, so that children with vestibular dysfunction may also have auditory-language processing problems.
It’s important to realize that the vestibular and auditory systems work together as they process sensations of movement and sound. These sensations are closely intertwined, because they both begin to be processed in receptors of the ear.
Audition, or hearing, is the ability to receive sounds. We are born with this basic skill. We can’t learn how to do it; either we hear, or we don’t. The ability to hear does not guarantee, however, that we understand sounds. We are not born with the skill of comprehension; we acquire it, as we integrate vestibular sensations. Gradually, as we interact purposefully with our environment, we learn to interpret what we hear and to develop sophisticated auditory processing skills. Some auditory processing skills include the following:
- Auditory discrimination – differentiating among sounds
- Auditory figure-ground – discriminating between sounds in the foreground and background
- Language – the meaningful use of words, which are symbols representing objects and ideas.
Language is a code for deciphering what words imply and how we use them to communicate. Language that we take in, by listening and reading, is call receptive. Language that we put out, by speaking or writing, is expressive. Language and speech are closely related, but they are not the same. Speech is the physical production of sound. Speech skills depend on smoothly functioning muscles in the throat, tongue, lips, and jaw. The vestibular system influences motor control and motor planning that are necessary to use those fine muscles to produce intelligible speech.
Because the vestibular system is crucial for effective auditory processing, the child with vestibular dysfunction frequently develops problems with language. How do these problems play out? Here are some common characteristics of children with poor auditory-language processing:
- May seem unaware of the source of sounds and may look all around to locate where the sounds come from.
- May have trouble identifying voices or discriminating between sounds, such as the difference between bear and bore.
- May be unable to pay attention to one voice or sound without being distracted by other sounds.
- May be distressed by noises that are loud, sudden, metallic, or high-pitched, or by sounds that don’t bother others.
- May have trouble attending to, understanding, or remembering what she reads or hears. She may misinterpret requests, frequently ask for repetition, and be able to follow only one or two instructions in sequence.
- May look to others before responding.
- May have trouble putting thoughts into spoken or written words.
- May talk off topic, e.g. talk about his new shirt when others are discussing a soccer game.
- May have trouble closing circles of communication. i.e. responding to others questions and comments.
- May have trouble correcting or revising what he has said in order to be understood.
- May have weak vocabulary and use immature sentence structure (poor grammar and syntax).
- May have difficulty with reading (dyslexia), especially out loud.
- May have trouble making up rhymes and singing in tune.
- May have difficulty speaking and articulating clearly.
- May improve her speaking ability after she experiences intense movement. Moving activates the ability to speak.
The child with vestibular and language problems benefits greatly from therapy that simultaneously addresses both types of dysfunction. Speech-and-language therapists report that just putting the child in a swing during treatment can have remarkable results. Occupational therapists have found that when they treat a child for vestibular dysfunction, speech-and-language skills can improve along with balance, movement, and motor planning skills. And even without the assistance of therapists, children who move spontaneously often show enhanced ability to verbalize their thoughts.