What is Auditory Processing Disorder?
What is Auditory Processing Disorder?
Auditory processing disorder (APD), also known as central auditory processing disorder (CAPD), is a form of hearing loss that impacts how the brain processes auditory input (Bellis, 2024; Mayo Clinic, 2023). While the exact prevalence of APD is unknown, some studies suggest between 2-5% of the pediatric population and 23-76% of adults 55 years and older may have APD (American Academy of Audiology, 2024; Cleveland Clinic, 2023).
How Does Hearing Occur?
Typical hearing occurs through a chain of events (Cleveland Clinic, 2023). First, sound waves enter the ear, hitting and vibrating the eardrum. This vibration causes the small bones in the middle ear to also vibrate, which triggers the inner ear fluid to ripple. The fluid then hits tiny hair cells within the inner ear, which sends signals to the auditory nerve. The auditory nerve sends signals to the brain, where the brain interprets the sense of sound (Cleveland Clinic, 2023).
For those with APD, the brain often has difficulties interpreting the signals from the auditory nerve, which leads to a misinterpretation of signals (Cleveland Clinic, 2023).
Common Challenges with APD
APD describes a variety of auditory deficits, rather than one singular event (American Academy of Audiology, 2024; Cleveland Clinic, 2023). These deficits may include:
What Causes APD?
While the exact cause of APD may vary, there are various risk factors for developing APD such as:
Stroke
Head trauma
Lead poisoning
Meningitis
Seizure disorders
Complications at birth or pregnant person using tobacco, alcohol, or drugs
Repeated ear infections, especially at a young age
(American Academy of Audiology, 2024; Mayo Clinic, 2023)
It is important to note that APD is often confused with other disorders that impact an individual’s ability to process auditory information, such as attention-deficit/hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) (Bellis, 2024). Individuals with ADHD or ASD may have difficulties listening to others and remembering or understanding verbal information. However, these challenges are due to higher-order cognitive global deficits. In contrast, APD occurs due to neural processing of auditory input (Bellis, 2024).
Common Symptoms of APD
Individuals with APD may experience a variety of symptoms, including difficulties with:
Understanding and remembering verbal information
Reading
Spelling
Paying attention
Remembering song lyrics while singing
Following directions that are not succinct
Identifying where a noise is coming from
Responding in a timely manner
(American Academy of Audiology, 2024; Bellis, 2024; Mayo Clinic, 2023)
Additionally, APD may impact students’ learning or communication with others, which may lead to anxiety or depression (Cleveland Clinic, 2023). Older adults may experience frustration and social isolation due to challenges with communication (American Academy of Audiology, 2024).
Diagnosis and Treatment
Individuals with ADHD, ASD, or learning disabilities may display symptoms of APD; however, they may not have actual neural deficits so it is important to seek out a diagnosis (mayo, (Bellis, 2024) An audiologist is the only healthcare professional who can diagnose APD.
Treatment for APD focuses on three primary areas:
Adapting or modifying the environment to increase access to information presented verbally, such as the use of noise-filtering headphones
Learning to compensate for auditory deficits, such as improving problem-solving, memory, attention, or other cognitive skills
Remediation of the auditory deficits, which may include one-to-one training, home-based programs, or computer-assisted treatment
(Bellis, 2024)
Interested in learning more about the auditory sensory system? Check out our blog post here!
References
American Academy of Audiology. (2024). Auditory processing disorders. https://www.audiology.org/consumers-and-patients/hearing-and-balance/auditory-processing-disorders/
Bellis, T. J. (2024). Understanding auditory processing disorders in children. American Speech-Language-Hearing Association. https://www.asha.org/public/hearing/understanding-auditory-processing-disorders-in-children/
Cleveland Clinic. (2023, April 21). Auditory processing disorder (APD). https://my.clevelandclinic.org/health/diseases/24938-auditory-processing-disorder
Mayo Clinic. (2023, September 30). Auditory processing disorder. https://www.mayoclinic.org/diseases-conditions/auditory-processing-disorder/symptoms-causes/syc-20555261