Central Auditory Processing Disorder (CAPD) - Symptoms & Causes

What is central auditory processing disorder (CAPD)?

Central auditory processing disorder (CAPD), also known as auditory processing disorder (APD), is a group name for a number of disorders that affect the hearing process. Although people with CAPD have normal hearing, their brains are unable to process and make sense of what they are hearing.

CAPD affects the auditory processing of both adults and children. The condition often starts in childhood, and boys are more prone to it than girls. It causes difficulty in understanding language due to a distortion of the auditory (hearing) signal.

Some main traits of CAPD in children are the inability to decipher speech in noisy places, difficulty following directions and conversations, poor decoding skills, distraction, and learning difficulties.

What are the symptoms of central auditory processing disorder (CAPD)?

The symptoms of CAPD can display in different forms and can range from mild to severe. They include:

• Late speech and language development
• Difficulty concentrating and understanding fast or unclear speech
• Difficulty replying to questions
• Being distracted and inattentive
• Frequently asking for information to be repeated
• Poor listening abilities
• Poor performance in big groups
• Poor self-esteem and anxiety
• Reading, writing and spelling difficulties
• Sensitivity to loud sounds
• Trouble finding the source of a sound
• Trouble telling the difference between sounds
• Trouble listening and understanding speech in noisy environments
• Trouble remembering information that was heard

Seek medical attention immediately if you observe that you or your child have trouble with hearing. An audiologist can do special tests to determine the problem and recommend suitable treatments.

What are the causes of central auditory processing disorder (CAPD)?

The exact causes of CAPD are not known. However, the following has been discovered:

• Abnormal processing of auditory information by the brain can be a result of the late development of the central auditory system.
• Children with neurological (brain and nerves) disorders, head injury and chronic ear infections can suffer from CAPD.
• Some developmental abnormalities have been linked to CAPD, such as attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), dyslexia and language impairments.

What are the risk factors of central auditory processing disorder (CAPD)?

There are factors that may increase the likelihood of developing CAPD:

• Low birth weight or premature birth. Premature infants (born more than 3 weeks before due date) and newborns weighing 2.5kg or below are at high risk of having CAPD.
• Ear infections in infancy and early childhood. Ear infections in children are caused by a virus or bacteria and may lead to fluid build-up in the eustachian tube, which clears mucus from the middle ear into the nasopharynx. When fluid does not drain normally from the middle ear, infection may develop. This often occurs when a child has a cold, sinus infection or allergies.
• Head injury during infancy. Serious head injuries related to accidents or child abuse may lead to bruises, bumps, cuts in the scalp or brain damage. Head injury is a risk factor for CAPD.
• Lead poisoning. This is the type of metal poisoning caused by the presence of lead in the body.

What are the complications and related diseases of central auditory processing disorder (CAPD)?

CAPD affects the brain's ability to filter and interpret sounds. Patients with this disorder have a hard time receiving, organising, and using auditory information.

They are able to hear, but unable to listen. If this is not addressed, it may cause complications such as brain maturation delays and brain traumas or tumours. Hence, it is always best to seek immediate medical attention when symptoms are present.

How to prevent central auditory processing disorder (CAPD)?

As the root cause of CAPD is still unknown, it is not possible to prevent it. However, you can prevent further learning disabilities and challenges by providing treatment for the disorder as early as possible.