Auditory processing disorder (APD)

What is auditory processing disorder?

Auditory processing disorder (APD) is a hearing problem that affects the way audio and oral information is taken in, meaning that those with APD have trouble understanding sounds and spoken words.

APD is thought to be a neurodevelopmental disorder, as those with the condition tend to have normal ear structure and function, but they are unable to process audible information, leading to difficulties with recognition, interpretation, and comprehension of words, sounds, music, and language. Anyone can have it, but it is most commonly diagnosed in children and older adults. APD is linked to other neurodevelopmental conditions like autism and ADHD, and so they may be comorbid within an individual. It is thought to be related to the central nervous system, and may occur due to issues such as strokes, head trauma, lead poisoning, seizures, chronic ear infections, and complications from birth.

What are the symptoms of auditory processing disorder?

Symptoms of APD include struggling with:

• Determining the origin of a sound
• Understanding words spoken quickly or loud environments
• Moderating personal volume when speaking
• Following along with instructions or stories unless simplified
• Learning new languages
• Singing or listening to music
• Understanding and remembering spoken information
• Understanding jokes, sarcasm, and vocal inflections (interpreting words literally)
• Receiving oral information
• Following conversations
• People with APD may additionally struggle with spelling, reading, and writing.

How is auditory processing disorder tested for?

When pursuing a diagnosis for APD, patients will take part in a series of tests, such as testing processing by:

• Listening to oral recitation with layered background noise, and then being asked to relay the information from the recitation (auditory figure-ground)
• Pointing out differences and changes in audios that are similar
• Two or more audios playing at the same time
• determining where sounds are coming from (binaural interaction)
• Measuring the amount of time it takes the patient to respond to questions or infer meaning (temporal processing)
• Filling in the missing parts or subtextual meaning of words and sentences (auditory closure)
• Speech and language tests
• Memory, problem-solving, and concentration tests

And there are also more technical tests to see how the brain and the ear react to sound, including:

• Having electrodes placed on the head to measure brain activity when introduced to audible stimuli
• Tympanometry, which sends bursts of air through the ear canal to measure the eardrum’s movement
• Audiometry exam, which evaluates hearing function of the inner ear
• Auditory brainstem response, which shows how the inner ear and brain pathways are working by using sensors that measure response to stimuli
• Acoustic reflex test, to see what happens in the ear when a loud sound is emitted

Treating auditory processing disorder (APD)

There is no known cure for APD at the moment, so treatment focuses on improving listening and concentration in what is called auditory training. It is conducted by a speech and language or hearing specialist, and the exercises will be designed based on the patient’s needs.. Some patients may be suitable for hearing aids and listening devices to concentrate and direct sound to improve understanding. There are also computer programmes to train the brain to better recognise and categorise sounds.