There is emerging and accumulating evidence that heading injuries, including concussions, can result in an Auditory Processing Disorder.

Auditory Processing simply refers to what we do with sound once we “hear” it. A person with an Auditory Processing Disorder (APD) presents with a persistent limitation in their ability to recognize and process sounds and speech effectively that is not caused by language or cognitive factors. Auditory processing disorders have also been described as what happens when the brain can’t hear. APD can have a significant impact on a person’s ability to function during everyday activities.

Auditory processing disorders can be developmental or acquired. Acquired auditory processing disorders can be caused by traumatic brain injury, degenerative neurological diseases and exposure to certain chemicals as examples.

Individuals with traumatic brain injury can display a variety of impairments including cognitive, language, psychological and sensory deficits, all of which have a detrimental effect on the how the person interacts in their community (Lew et al. 2007). Traumatic brain injury can cause damage to both the peripheral and central auditory pathways. It has been estimated that over 50% of individuals with traumatic brain injury may have an auditory processing disorder (Musiek et al 2004) (Bergemalm & Burg 2001). In fact, the Canadian Guidelines on Auditory Processing Disorders indicate that auditory processing disorders are so prevalent for individuals with traumatic head injury that auditory processing testing should be routinely conducted for these clients (CAA 2010).

Case Study: So what does an auditory processing disorder from a head injury look like? In this case study, a woman is involved in a motor vehicle accident in which she sustains a “concussion”. She complains shortly after the accident that she can’t seem to hear as well in crowds and has difficulty understanding speech with foreign accents. She had a hearing test done and was told she had “normal” hearing. However, basic hearing tests only look at the peripheral part of our hearing system. When someone notices a change in their ability to understand and communicate after a head injury, we would want to assess how well a person can efficiently and accurately process sound when it travels from the inner ear, through the brain stem and up to the auditory portions of our brain, specialized tests can be conducted (APD Testing) In this case study, the woman’s APD test results confirmed that she has an auditory processing disorder that was likely the result of the “concussion” she sustained in her car accident. The woman is now receiving therapy including treatment to improve her ability to hear in the presence of background noise (a form of auditory training called Dichotic Listening Training).