Central Auditory Processing Disorder

The scope of this page is central auditory processing disorder (CAPD) in children and adults. Content is relevant to both developmental and acquired CAPD; however, this page does not specifically address adult acquired CAPD from causes such as brain injury, disease, or factors of aging.

See the Central Auditory Processing Disorder (CAPD) Evidence Map for summaries of the available research on this topic.

Hearing-related terminology may vary depending upon context and a range of factors. See ASHA’s resource on hearing-related topics: terminology guidance for more information.

The ASHA Practice Portal aims to provide access to the best available evidence, expertise, and resources to support the individual clinical decision making of professionally educated clinicians. Long-standing variation in perspectives within the professions of audiology and speech-language pathology regarding the diagnosis, assessment, and treatment of CAPD makes the need for informed clinical decision making of paramount importance.

Central Auditory Processing

Central auditory processing—also seen in the literature as (central) auditory processing or auditory processing—is the perceptual processing of auditory information in the central auditory nervous system (CANS) and the neurobiological activity that underlies that processing and gives rise to electrophysiologic auditory potentials.

Knowledge of the neuroanatomy and physiology of the CANS is essential for understanding and interpreting underlying processes and deficits. Medwetsky (2011) provides in-depth information on this topic.

Central auditory processing consists of mechanisms that preserve, refine, analyze, modify, organize, and interpret information from the auditory peripheral system. These mechanisms underlie skills such as auditory discrimination, temporal aspects of audition, and binaural processing (ASHA, 1996; Bellis, 2011; Chermak & Musiek, 1997).

Central Auditory Processing and Language Processing

There is general agreement that auditory perceptual abilities and language development are interrelated—as are auditory processing skills and pre-literacy skills (Corriveau et al., 2010)—and that it can be difficult to separate the influence of auditory and language skills with regard to academic demands (Richard, 2012, 2013). The act of processing speech is complex and involves the engagement of auditory, cognitive, and language mechanisms, often simultaneously (Medwetsky, 2011).

Richard’s (2013, 2017) continuum of processing includes both auditory processing and language processing. This continuum involves the following types of processing:

  • central auditory processing, in which the neural representation of acoustic signals is processed after they leave the cochlea and travel through the auditory nervous system to the primary auditory cortices of the left and right hemispheres
  • phonemic processing, in which phonemic skills such as sound discrimination, blending, and segmenting are utilized to discriminate acoustic features of the signal
  • linguistic processing, in which meaning is attached to the signal

Central Auditory Processing Disorder (CAPD)

Terms used to describe a disorder in the processing of auditory information may vary based on the perspective of the professional describing the problem. Terms include, but are not limited to, “auditory processing disorder,” “(central) auditory processing disorder,” “language processing disorder,” and “auditory information processing disorder.”

ASHA (2005) uses the term central auditory processing disorder (CAPD) to refer to deficits in the neural processing of auditory information in the CANS (not due to higher order language or cognitive factors) demonstrated by poor performance in one or more of the following skills:

  • sound localization and lateralization
  • auditory discrimination
  • auditory pattern recognition
  • temporal aspects of audition
  • auditory performance in competing acoustic signals
  • auditory performance with degraded acoustic signals

This terminology aligns with the National Center for Health Statistics classification of the diagnosis within the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM).

Although sometimes difficult, careful differential diagnosis is important to the process of treatment planning:

  • CAPD may lead to or be associated with difficulties in higher order language, learning, and communication functions.
  • CAPD may co-occur with (and necessitate differentiation from) other disorders (e.g., attention-deficit/hyperactivity disorder, language delay or disorder, and learning disability).
  • CAPD is not due to peripheral hearing loss, whether conductive (i.e., involving the outer or middle ear) or sensorineural (i.e., involving the cochlea or auditory nerve).
  • CAPD is not due to multilingualism.

Professionals have adopted varying perspectives on the interpretation of CAPD (Buehler, 2012; Cacace & McFarland, 2009; DeBonis, 2015; de Wit et al., 2016; Friberg & McNamara, 2010; Jerger, 1998; Jutras et al., 2007; McDermott et al., 2016; McFarland & Cacace, 2006; Moore et al., 2010; Rees, 1973, 1981; Richard, 2011; Sharma et al., 2019). These different perspectives reflect ongoing debate regarding how to define, assess, and treat CAPD.

Different viewpoints on CAPD exist for several reasons, including the heterogeneity of symptoms, variations in the definition, the lack of a reference standard for diagnosis, the relationship between auditory perceptual deficits and language disorders, and the particular treatment approach(es) that follow from the diagnosis (Bellis & Ferre, 1999; Kamhi, 2011; Katz et al., 1992; Moore, 2018; Moore et al., 2013; Vermiglio, 2014). For example, some professionals propose that a CAPD diagnosis may indicate a broader language-based disorder necessitating language treatment targets (DeBonis, 2015; de Wit et al., 2016; Kamhi, 2011). Some suggest that CAPD be diagnosed by specific deficit (e.g., difficulty processing signals in noise; difficulties with auditory discrimination, temporal processing, or binaural processing) rather than broadly as CAPD because of the diverse skills involved in auditory processing (Vermiglio, 2016).

Of note, not all diagnoses of CAPD represent a limitation for the individual (Dillon et al., 2012) or a condition that must be treated (Vermiglio, 2016).

Team Approach

A person- and family-centered plan of care for CAPD ideally involves a team of professionals. The composition of an interprofessional team varies based on the needs of the individual, who (along with their support system) is integral to the process (e.g., planning, decision making, service delivery). See the ASHA resources on interprofessional education/interprofessional practice (IPE/IPP) and Focusing Care on Individuals and Their Care Partners as well as the ASHA Practice Portal pages on Multilingual Service Delivery in Audiology and Speech-Language Pathology and Cultural Responsiveness.

Content Disclaimer: The Practice Portal, ASHA policy documents, and guidelines contain information for use in all settings; however, members must consider all applicable local, state and federal requirements when applying the information in their specific work setting.

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