Auditory Processing Disorder in Children
What Is APD, What Causes APD And Why Does It Undermine Learning?
Central auditory processing disorder (CAPD or APD as is now more common) is a disconnect between how an individual hears sound and how sound is processed. In most cases, there is no hearing loss or neurological disease involved. Because it impacts internal skills — listening, working memory, thinking — auditory processing disorder can be difficult to detect.
APD is not a condition or affliction, but rather an auditory deficit, where the cognitive makeup of the brain as a whole is unable to process sound accurately. Below certain thresholds in testing, the lack of auditory development or skill in sequencing and sound discrimination leads to an auditory processing disorder diagnosis.
Auditory Processing Deficits Are More Common Than You Might Think
Most experts calculate that diagnosed auditory processing disorder affects between 2% and 7% of the population. Certainly over the past decade it is being recognized and diagnosed more frequently. However, when you include undiagnosed processing delays, estimates for APD rise to as high as 10-20% of the population (Cooper and Gates, 1991). For struggling readers, the number is significantly higher.
Actually, auditory processing delays are probably even more pervasive than the Cooper and Gates estimate. A ten-year study by the Institute of Health and Child Development (1985-1995) found that 88% of reading difficulties were caused by weak phonemic awareness, the ability to pick out the sounds inside words. Phonemic awareness requires sound auditory processing.
Since 40%+ of the population read below grade level (per the NIH), 35% of the population probably have under-developed auditory processing skills, one in three. This is not surprising. Processing at natural language speed, listening for comprehension and picking out phonemes, is one of the brain’s most challenging tasks. It requires processing at up to 40 sounds per second.
Because of the avoidance behaviors that stem from reading and learning difficulties, many children with APD actually end up being diagnosed with something else, either ADHD, developmental dyslexia or another learning disability.
What Causes Auditory Processing Disorder?
The primary auditory processing disorder causes have their roots in the amount of language your child is able to hear accurately in early life. Auditory processing skills develop naturally through daily language interaction and stimulation — listening and talking.
In most cases, there is sufficient stimulation around a child to develop fully formed language processing skills by the age of 6 or 7. At this age most children can comprehend spoken language at natural language speed and they can pick out phonemes, the sounds inside words, for reading. The most crucial time in this development of these crucial and complex skills in the central auditory nervous system is the first three years of life.
A famous study, the “Early Catastrophe” by Hart and Risley, found children in professional homes hear 30 million more words than their peers in lower income homes over their first three years of life. Researchers refer to it as the “30 million word gap.” This cumulative language experience amounts to extra stimulation and practice for auditory processing skills that translate into a faster start in learning and reading.
Interruptions in Listening Can Cause APD
Therefore, the primary cause of auditory processing disorder in children is a lack of language stimulation in early life. Or alternatively, it is an interruption in that language stimulation due to an unusual number of childhood viruses, recurring ear infections, degenerative disorders, glue ear and other hearing glitches. These interruptions deprive a child of language interaction practice in those crucial first three years of life. This early childhood form of auditory processing disorder is developmental APD.
Two terms are interchangeable — auditory processing disorder and language processing disorder (LPD). This is an important distinction in adoption cases where a child is not born hearing English. English is phonetic, whereas for instance, Mandarin is tonal. A Chinese-born child who moves to America at the age of one will need to start mapping the language all over again. As a result, even if his auditory processing skills are reasonable, he is at risk for LPD because his three year language development window is only two years.
Outside Trauma Can Cause APD
Acquired APD on the other hand refers to auditory processing disorder causes from an outside event. This might include head trauma, chemotherapy or a disease, such as viral meningitis. Acquired APD is less common, but similarly caused by a general lack of cognitive skill functioning that impacts language processing.
About 40% of learning disabilities are hereditary. Auditory processing disorder fits into this pattern, it runs in families.
Finally, we should note that the most common cause of auditory processing disorder in children is “none of the above”. It’s a tough skill to master, and many children simply require more time and stimulation than their surrounding environment provides.
How APD Undermines Learning
There is a correlation between auditory processing skill and learning outcomes. Children with auditory processing deficits are slow to learn to read and to write. And so yes, auditory processing is the most common learning skill you may have never heard of.
Auditory processing is a fundamental cognitive skill because it determines language mastery, the gateway to reading and learning. Children whose language processing skills do not mature and develop are at risk for difficulties in:
- Learning — listening accuracy and comprehension
- Reading — a language skill
- Social interaction
- Thinking — internal dialog uses language
Delays in auditory processing also impede development of working memory (related to IQ), attention skills and higher level thinking and learning. Furthermore, for children with auditory processing difficulties reading comprehension is almost always a challenge. If letter sounds are not clear, reading can’t be automatic. It will require constant concentration and extra effort.
Hypersensitive auditory processing disorder, a hypersensitivity to background noise, is another factor that impacts learning. A child’s intolerance to ‘usual noises creates disrupts the learning routine in a way that over time adds up.
A Child’s Day With Auditory Processing Disorder
Auditory processing disorder in children can be very challenging. When we are young, our day job is school. Our primary focus is getting an education. With auditory processing disorder, a child’s school day may be more challenging, frustrating and sometimes humiliating than anyone realizes.
- He may be missing much of what the teacher is saying in class, particularly in noisy classrooms.
- Homework can be frustrating and stressful. This stems from not understanding the assignment, an inability to follow the lesson in class and/or reading problems.
- Social conversations with peers are challenging, particularly in noisy playgrounds.
- Sometimes she faces humiliation, having to answer in class before she understands the question.
- Reading out loud in class or to a parent is often another daily struggle.
These daily frustrations erode confidence and self-esteem. Furthermore, they create a negative connection to reading and learning that over time will be hard to reverse. Consequently, many children with APD do eventually grow out of their processing delays, but they never do become enthusiastic readers.
How To Identify APD and What To Do Next
As you might expect, being aware of central auditory processing disorder causes and therefore recognizing auditory processing disorder in children early on is important. ASHA, the American Speech-Language Hearing Association, recommends formal testing through an audiologist. This testing normally occurs in a sound room. Different volume levels and sound combinations test temporal aspects of auditory discrimination (sequencing), auditory pattern recognition and the ability to process degraded or distorted sound.
However, since auditory processing impacts a range of behaviors, there are tell-tale signs of APD you can observe using a symptoms checklist with signs of auditory processing disorder in children listed by age.
If you decide on formal testing, you will receive advice on managing auditory processing disorder for your child at home and at school. However, that is about all you will get. There is no medicine or magic pill for APD. It is a delay in cognitive skill growth. And just like other physical or cognitive skills, the only way to improve auditory processing skills is with exercise.
Using Exercises To Train Auditory Processing
This is where software therapies Fast ForWord have come into prominence. Helping auditory processing disorder in children and in adults. The software presents a range of adaptive exercises that progressively steepen in difficulty, therefore pulling the student up to higher levels of processing efficiency. These exercises are intense, the equivalent of hearing millions of words in just a few months.
Because cognitive skills respond to exercise relatively quickly, there is value in checking out treatments suitable for your child. While not always successful, dramatic gains in processing are more common than you might think.