"Garbled." That is how Diane described communicating with her fiancé George. Once she met him at her front door with a warm smile, noticed mud on his shoes, and asked him to leave his boots on the stairs. Puzzled, he said, "Your suits stare? What?"
Despite Diane's clarification, George insisted that she had said exactly that — and in a disapproving tone of voice.
Given the couple's tangled talk, and George's penchant for watching TV at full volume, Diane thought he had a hearing problem, but testing nixed that theory. The couple's therapist suggested that George had a deep-seated resistance to listening to Diane, so he blocked her out. Diane didn't buy it: "It's not that he wasn't listening or didn't want to listen. He was looking right at me, paying attention. But the message had been sliced and diced on the way from my mouth to his understanding of what I'd said." Diane was right.
Just as their miscommunication reached fever pitch, George was diagnosed with attention deficit hyperactivity disorder (ADHD). The couple was relieved when the cognitive therapist explained to them that ADHD has a common comorbid condition called Central Auditory Processing Disorder (CAPD). Simply put, CAPD causes a person to misinterpret what someone is saying and the tone of voice in which it is said.
Central Auditory Processing Disorder (CAPD) and ADHD
Their therapist gave George and Diane strategies for enhancing communication. The couple also discovered that stimulant medication may rectify misinterpretation by "strengthening the signal," the neurochemical pathway from the ear (where sound waves enter) to the brain's auditory processing cortex (where sounds are interpreted and given meaning). "We've had hardly any garbled messages since George started taking medication for his ADHD," says Diane.
"There's no tiny speaker inside your brain that relays messages from the outside," explains neurologist Martin Kutscher, M.D., author of Kids in the Syndrome Mix of ADHD, LD, Asperger's, Tourette's, Bipolar, and More! "What you think you ‘hear' is a virtual-reality recreation of sounds that stopped at your eardrum and, from there on, exist as soundless electrical impulses."
Here's what happens in an exchange between speaker and listener:
- The speaker's vocal cords produce a sequence of vibrations that travel invisibly through the air and land on the recipient's eardrums.
- The listener's eardrums vibrate, causing movement of three tiny bones that, in turn, stimulate the cochlear nerve. This is essentially where "sound" ends.
- From this point, what the listener thinks he "hears" is actually a series of silent electrical stimuli carried by neuronal wires.
"The brain processes these electrical impulses into sounds, then into words, and then into meaningful sentences and ideas," says Kutscher. "Most of us do it effortlessly. Some adults have problems in converting these electrical neuronal impulses into meaning. We call these problems Central Auditory Processing Disorders."
ADHD or Auditory Processing Disorder?
We hear a lot about children having CAPD or Auditory Processing Disorder (APD). But psychologists and psychiatrists seldom use these terms, which originate in the speech and language profession. Limited evidence suggests that Central Auditory Processing Disorder (CAPD) is sometimes a condition separate from ADHD. Yet, as one review paper summarized: "Whether the child (or adult) receives the diagnosis of CAPD or ADHD may depend on whether an audiologist or a psychologist assesses the person first."
A rigorous reading of the literature points to a "discipline bias" -- the condition is diagnosed differently, depending on the professional's area of specialty. The difference lies in the type of treatment available — an important distinction, because research in this area suggests methylphenidate (the generic name for the medication in Ritalin and Concerta, for example) can improve CAPD symptoms, often dramatically.
By contrast, nonmedical interventions for CAPD are limited to strategies such as using electronic devices and altering the learning environment (less ambient noise).
The following characteristics of CAPD, from the National Institute on Deafness and Other Communication Disorders, sound similar to those of ADHD:
- Has trouble paying attention to and remembering information presented orally
- Has problems carrying out multi-step directions
- Has poor listening skills
- Needs more time to process information
- Has behavior problems
- Has difficulty with reading, comprehension, spelling, and vocabulary.
Children with ADHD may be misdiagnosed with CAPD, but if an adult has subpar listening ability, he may be perceived as passive-aggressive, oppositional, withholding emotionally, or argumentative, rather than as an individual with attention deficit.