The Challenge of Central Auditory Processing Disorder

Children with Central Auditory Processing Disorder (CAPD) are easily distracted and cannot focus on an auditory task for very long.

The more challenging the acoustic environment the harder it is to follow speech and verbal instructions.

CAPD medical definition: Central Auditory Processing Disorder: also known as Auditory Processing Disorder is a disorder that is marked by a deficit in the way the brain receives, differentiates, analyses, and interprets auditory information such as speech. CAPD is not attributable to impairments in peripheral hearing or intellect.

Auditory Processing – the Function of Hearing

Auditory Processing refers to the function of hearing, and ultimately the translation of sounds into meaning performed at the central parts of the brain named the auditory cortex.

To interpret and respond to auditory information, the brain receives signals originated by sounds coming from the external world that first enter the ear canal, vibrating the eardrum, passing the middle ear, the cochlea and the auditory nerve through the brainstem all the way to the auditory cortex.

Speech is an Auditory Signal to be Processed

Speech is the most important auditory signal used for communication. Interpretation of speech signals requires a set of auditory skills that allow processing to occur. Several analyses take place before a sound can be fully processed.

To understand a verbal stimulus one needs to be able to identify the sounds, discriminate the differences in tempo, pitch, loudness, sequence, localise and focus on the source of sound at the task and ignore others that are not important.

Two Ears = a Binaural System

The sense of hearing is a binaural system, as it relies on the input from our two ears. Interaction and integration of the signals coming from the right and left ears at the brainstem, midbrain and auditory cortex level need to be intact for appropriate processing to occur.

Central Auditory Processing Disorder Can Lead to Impaired Skills

A breakdown in one or more of the skills required in the process may result in an auditory processing disorder. An auditory processing disorder may be diagnosed with specialised audiological assessment when the impaired skills are identified and individualised therapies recommended.

Preventions and Correction of CAPD

Prevention by maintaining a healthy body is by far the best remedy but even when an auditory processing disorder is already established, there are measures you can take to overcome the adverse effects and consequences for your child’s development.

Auditory processing disorder (APD) also known as central auditory processing disorder (CAPD) is a common finding amongst children with atypical development, behavioural and learning difficulties. (1).

Children Affected by Ear Infections

Young children prone to “glue ear”, middle ear infection or otitis media are commonly diagnosed with an auditory processing disorder when starting school (2). Temporary diminished hearing commonly caused by ear infections deprives the brain of the appropriate auditory input required for the natural development of auditory processing skills.

Allergies that affect the upper respiratory tract (nose and throat) are common triggers of recurrent middle ear infections (3, 4) and consequent APD.

Auditory Processing Disorder can also be Unrelated to Ear infections

There are also a number of children diagnosed with APD who have had no previous episodes of ear infection but may have other issues affecting their immune system and brain development.

Auditory processing ~ “what the brain does with what we hear”

Auditory processing is commonly defined as “what the brain does with what we hear” (5). More specifically, auditory processing is a set of skills required to analyse sound information during its transmission from the ears to the brain so that it can be interpreted and dealt with appropriately.

The Sense of Hearing and Auditory Processing

Auditory processing is a sensorial processing through the organ of hearing. Sensorial processing is a generic term referring to the use of our senses to understand and connect to our surrounding environment (6).

See also: Sensory Processing Depends on 6 Senses for further discussion on other sensorial processing

 

References:

  1. Kraus, Nina, et al. “Auditory neurophysiologic responses and discrimination deficits in children with learning problems.” Science 273.5277 (1996): 971.
  2. Gottlieb, Marvin I., Peter W. Zinkus, and Anne Thompson. “Chronic middle ear disease and auditory perceptual deficits: is there a link?.”Clinical Pediatrics18.12 (1979): 725-732.
  3. Nguyen, Lily HP, et al. “Similar allergic inflammation in the middle ear and the upper airway: evidence linking otitis media with effusion to the united airways concept.” Journal of allergy and clinical immunology 114.5 (2004): 1110-1115.
  1. Teele, David W., Jerome O. Klein, and Bernard A. Rosner. “Epidemiology of otitis media in children.”Annals of Otology, Rhinology & Laryngology89.3_suppl (1980): 5-6.
  2. Jerger, James, and F. Musiek. “Report of the consensus conference on the diagnosis of auditory processing.”Journal of the American Academy of Audiology11.9 (2000): 467-474.
  3. Dunn, Winnie. “The Impact of Sensory Processing Abilities on the Daily Lives of Young Children and Their Families: A Conceptual Model.”Infants & Young Children9.4 (1997): 23-35.