About Auditory Processing Disorder (APD)

Overview

Auditory processing disorder (APD) is a condition where the central auditory nervous system has trouble processing and interpreting sounds, even though the ears work properly. It involves difficulties in how the brain organizes and interprets sound signals, both from incoming information (bottom-up) and higher-level thinking and context (top-down). People with APD typically have normal hearing sensitivity as measured by pure tone audiometry. However, they struggle with processing and interpreting auditory stimuli, especially in complex situations or with background noise. APD is not typically linked with structural brain lesions (areas of damage in the brain) that can be seen on brain imaging, but there may be subtle abnormalities in the central auditory pathway (the system in the brain that processes sound). Some individuals with APD may also show abnormal auditory brainstem responses (a test that measures how sound signals travel from the ear to the brainstem). APD affects more than just how sound is sent through the ears and auditory nerve. It also impacts how the brain understands speech and other complex sounds. Traditional hearing tests may not fully capture problems with understanding and processing sounds.

Causes and Risk Factors

The causes of auditory processing disorder (APD) can include:

• Neurological conditions
• Central nervous system development delays
• Coexistence with other developmental disorders
• Recurrent middle ear infections
• Hearing loss from sensory deprivation

Non-modifiable risk factors for APD cannot be changed or controlled. These include:

• Hereditary factors
• Neurological disorders or developmental delay
• Multiple ear infections

Modifiable risk factors for APD can be influenced or changed. These include:

• Exposure to loud noise
• Certain medications that can affect hearing
• Nutritional deficiencies
• Smoking
• Excess body fat
• Low socioeconomic status

It's important to note that while these factors may contribute to the development of APD, it is a complex condition and individual cases may vary. It is always recommended to consult with a healthcare professional for a comprehensive evaluation and personalized advice.

Symptoms

The most common early symptoms of auditory processing disorder (APD) include:

• Difficulty understanding speech, especially in noisy environments or when multiple people are speaking
• Frequently asking people to repeat what they've said or responding with words like "huh" or "what"
• Misunderstanding what's been said
• Needing more time to respond during conversation
• Trouble telling where a sound is coming from
• Problems distinguishing between similar sounds
• Difficulty concentrating or paying attention
• Problems following or comprehending rapid speech or complex directions
• Trouble with learning or enjoying music

As APD progresses or becomes more severe, other common symptoms may occur, such as:

• Increased difficulty listening, especially in noisy settings
• Greater difficulty following spoken instructions
• Asking for people to repeat speech, which may appear similar to having difficulty hearing
• Difficulty receiving verbal information

It's important to note that a doctor cannot diagnose APD based on symptoms alone, as there may be other causes for communication, language, or learning difficulties. To diagnose APD, an audiologist can conduct tests that assess responses to sound. Remember to consult with your healthcare professional for personalized advice and guidance.

Diagnosis

To diagnose auditory processing disorder (APD), a combination of examinations, tests, and procedures are typically performed. These include:

• History evaluation: Thoroughly assessing your symptoms, their onset, and any risk factors for APD
• Audiological assessment: Conducting various hearing tests to evaluate how well the outer, middle, and inner ear, as well as the auditory nerve, detect and send sound to the brain such as:
  • Air conduction and bone conduction: Measure how well sound travels through the ear (air conduction) and directly through the skull to the inner ear (bone conduction)
  • Speech reception threshold (SPT): Determines the quietest level at which a person can recognize and repeat words
• Tympanometry: Examining the middle ear function by measuring the movement of the eardrum in response to changes in air pressure
• Acoustic reflex testing: Assessing the reflexive contraction of the middle ear muscles in response to loud sounds
• Central auditory processing testing: Evaluates how well the brain processes sounds and includes tests like:
  • Sound localization: Measures the ability to identify where a sound is coming from
  • Level discrimination: Checks how well a person can tell the difference between loud and soft sounds
  • Temporal patterning: Tests the ability to recognize patterns in sound over time
  • Temporal integration and discrimination: Measures how well sounds are processed when presented close together in time
  • Word recognition in challenging listening conditions: Assesses how well a person understands words in noisy or difficult environments
• Multidisciplinary approach: Involving professionals from various fields like audiology, psychology, speech-language therapy, and education to rule out other potential causes and assess cognitive functioning, communication skills, and learning challenges.

To determine the severity of APD, additional examinations and tests may be conducted:

• Battery of tests: A series of tests used to evaluate different auditory processing skills and how well a person performs across various areas of hearing and sound interpretation

Remember that accurate diagnosis and determining the stage or severity of APD require professional evaluation by healthcare providers specializing in auditory processing disorders.

Treatment Options

The goals of treatment for auditory processing disorder (APD) are to improve sound processing, enhance compensatory skills, and create a supportive environment. Here are the various treatments and their mechanisms for achieving these goals:

• Auditory training: This therapy focuses on improving sound analysis and can be done through one-on-one sessions with a therapist or online. Exercises include identifying sound differences, determining sound location, and focusing on specific sounds in the presence of background noise.
• Compensatory strategies: These strategies aim to strengthen memory, attention, and problem-solving skills to help manage APD. Examples include predicting conversation elements, using visual aids to organize information, incorporating memory techniques like mnemonic devices, and learning active listening techniques.
• Changes to environment: Making adjustments to the surroundings can also aid in managing APD. This may involve reducing auditory distractions, working in a quiet environment, and using self-help strategies such as organizers or reminder lists.
• Medication: While medication is not a primary treatment for APD, it may be considered if there is an underlying condition like ADHD. Treating ADHD with medications like methylphenidate has been found to potentially alleviate auditory processing symptoms. However, medication options specifically for APD are not available.

It's important to note that treatment for APD is individualized based on evaluations conducted during the diagnostic process. Therefore, it is essential to consult with healthcare professionals who can provide personalized recommendations and guidance.

Medication dosing may be affected by many factors. Check with your health care professional about dosing for your individual situation. Other side effects can occur. Check with your health care professional or read the information provided with your medication for additional side effect information.