What More Can We Say About Central Auditory Processing (CAP)?

By Geraldine P. Wallach, Ph.D., CCC-SLP & Alaine Ocampo, Ph.D., CCC-SLP

Geraldine-Wallach-blog.jpg       Alaine-Ocampo-blog.jpg

February 25, 2021

Introductory Points and Questions

Because many assessment tools often tap overlapping skills and abilities, it is important for speech-language pathologists (SLPs) to take a closer look at both the conceptual model from which the test was devised and its standardization methodology, among other factors that influence their choices about which instruments to choose to measure where a student might be along the language literacy continuum. SLPs should also consider whether a test’s label, including its various subtests, provides clinicians with an accurate picture of what is actually being tested. For example, are subtests with labels of “word discrimination” or “auditory discrimination” testing more than they appear to test? Are all “auditory comprehension” subtests created equal? In essence, the question we might ask ourselves is: “Have we looked carefully enough about ways in which a test or subtests therein can require closer analysis?” In this article, we ask an even more specific question: How do we begin to pull together several interacting skills often interpreted under the broad-based heading of “central auditory processing” in a coherent and meaningful way? We will address ways that SLPs can interpret aspects of auditory processing more broadly and, ultimately, taking some practical steps to get beyond broad-based diagnostic categories like “central auditory processing disorders” (CAPD) that may lead us to less effective intervention choices.

Five Key Points About Several Dynamic Aspects That Relate to Language and Auditory Processing Interactions

(1) When listeners function in the real world, many things happen simultaneously. Abstract models of language that define “steps” in the process from when the message hits the ear and beyond to when a word, sentence, story or essay is understood represents much more than a clear-cut step-by-step sequential or linear process. Rather, this series of processes from ear to brain to comprehension and interpretation represent fluid, dynamic events whereby so-called “higher” levels (e.g., like knowing what a word means and using it appropriately) influence so-called “lower” levels (e.g., like being able to discriminate whether word pairs sound the same or different) (e.g., Kamhi, 2011, 2014; Nittrouer, 2002; Ocampo & Wallach, 2018)

 (2) Using language spontaneously for communication and when comprehending messages in various conversational contexts is not the same as demonstrating metalinguistic ability that includes manipulating and judging aspects of language consciously (e.g., deciding whether two words sound the same or different) or trying to process language in academic settings (e.g., a teacher’s instructions within a large classroom)

 (3) Background knowledge cannot be underestimated when testing processing, comprehension, and memory in both spoken and written domains. Familiar and unfamiliar materials should be compared when conclusions are being reached about a student’s processing span, spoken language comprehension, and memory (Catts & Kamhi, 2017; Keenan, 2014; Wallach & Ocampo, 2017)

 (4) The reciprocity between spoken and written language systems should be kept in mind since written language ability influences language and processing across time and contexts and helps us create organizational strategies that can influence how and what we retain ( e.g., Bashir & Singer, 2006; Dockrell, 2014). Standardized tests are closer to print than spoken language (Catts & Kamhi, 2012) so readers may outperform non-readers, a factor that should be noted

 (5) Test items may provide a “tip pf the iceberg” glimpse into a student’s weaknesses and encourage us to dig further to understand the ways that results on any standardized test, particularly those tests tapping auditory processing in isolation and in quiet laboratory-like contexts, show themselves in the processing, comprehension, and retention within classrooms and other communication contexts. Indeed, whether we use the terms “auditory processing” or “language processing,” we know that problems reside both inside and outside of kids’ heads (Nelson, Personal communication, 2019). In other words, what children are being asked “to process” makes a difference (e.g., social studies or science texts versus familiar stories and themes, etc., taken together known as the study of disciplinary literacy). Likewise, the situation in which the listener finds himself or herself facing (e.g., home language, classroom language, test language) also form “outside the head” considerations.

These five points address the challenges facing professionals who must decide how to operationalize these concepts into a practical roadmap. While framed under the heading of “auditory processing skills,” a term known to readers of this article, the term and its diagnostic power, as already suggested, requires closer scrutiny. Indeed, looking beyond what a test or subtest’s label or diagnostic classification might suggest, is critical for driving intervention in the most appropriate and relevant directions (Vermiglio, 2014, 2016; Wallach, 2011).

The Evolution of Auditory Processing and Language Connections: Still Controversial

Professionals who use auditory processing tests or refer to subtests that address a wide range of so-called “auditory” abilities (e.g., word discrimination tasks, auditory memory tasks, auditory comprehensions tasks) are well aware of the decades of research, task forces, blogs, presentations, and discussions, among other forums, that have addressed the role of (Central) Auditory Processing (CAP), Central Auditory Processing Disorders (CAPD), and Auditory Processing (AP) (without the “Central”) in language and academic learning. (See, for example, Fey, et al. 2011, a now-classic in the Language, Speech, and Hearing Services in Schools journal for a summary of the American Speech-Language-Hearing Association’s Committee on Central Auditory Processing Disorders, among other articles in the issue.) While much information exists “out there,” there is little agreement about the viability of CAPD/APD as a unique, and singular clinical entity (e.g., deWit et al., 2016; Vermiglio, 2014, 2016) and the efficacy of auditory processing interventions for language and academic learning (e.g., Kamhi, 2011, 2014). What further complicates the challenges for practitioners about the use of APD diagnosis clinically and educationally is that advocates of APD lack consensus about definition, evaluation, and treatment (e.g,  Burkard, 2009; Fey et al., 2011)..  

Whereas we may appreciate Burkard’s and others’ cautionary works, in the real world, the term “auditory processing disorder” (APD) is used frequently by specialists, teachers, and parents to describe students with a variety of language learning and other communication and learning problems (Wallach, 2011). While an in-depth history and summary of the different points of view about AP and AP disorders throughout the millennium (see Rees’ classic 1973 article; also McFarland & Cacace, 2006) is out of the realm of this paper, it may be relevant to delve a bit further into the AP-Language controversy.

Professionals’ Diverse Perceptions About AP Disorders

Many professionals characterize auditory processing disorders using various descriptive phrases that mirror the definitions from the literature and that are covered in many assessment tools.  For example, one might hear: “My student has a problem with auditory discrimination.” Other terms heard to describe students’ processing (or comprehension issues) include: “The child has a problem with auditory sequence, auditory figure-ground, auditory blending, and/or auditory synthesis.” These popularly-used terms, among others, capture the auditory processing weaknesses demonstrated by many students with language learning difficulties. The question for us becomes twofold: Are these identified deficits the “tip-of-the iceberg?” and Should we work directly on these skills to strengthen language, reading, and/or other aspects of academic learning (see ASHA, 2005; Kamhi, 2014; Ocampo & Wallach, 2018)?  Some professionals, those more closely aligned with the auditory processing and disorders’ view, see the core of children’s/students’ problems along the auditory landscape as foundational and cause-effect elements on the processing/spoken language comprehension continuum. Others, including the authors, agree that children demonstrate characteristics and symptomatology in “auditory” processing but see these symptoms as part of a larger language issue. Indeed, language proponents have a different view about the significance of certain auditory perceptual symptomatology like children’s performances on dichotic listening tasks and temporal processing tasks and we see these gaps as connected to language knowledge and competence. But regardless of our perceptions and opinions, we should all ask: What do the dichotic listening stimuli consist of? (Narratives, sentences, isolated non-speech sounds?) And are findings relevant beyond a theoretical framework?

Other differences between auditory and language camps may relate to the way professionals view the dynamic interplay among internal and external factors and the way these factors interact over time, a point mentioned earlier in this discussion. “Internal” factors relate to those abilities the child brings to a task or situation (i.e., what knowledge, skills, and strategies the child “comes with”) as well as “external” factors (i.e., the teacher’s instructional style, the text, the content area subject demands, the context). Focusing primarily on “internal” factors with the intent to “fix” internal system gaps (e.g., AP gaps) represents only part of the picture (Wallach, 2011). And again, regardless of one’s perspective, it is important to recognize the complexity of factors and share an understanding that there are more complex and integrated linguistic operations that override auditory processing factors (e.g., ASHA, 2005; deWit et al., 2016; Dewitz, Jones, & Leahy, 2009; Medwetsky, 2006, 2011).

Final Thoughts: Some General and More Specific Suggestions

General Concepts

Adapted from Wallach, Vermiglio, and Kamhi (2016), here are a number of key points for reflection:

1.)    Interpret auditory processing weakness from a broader perspective that encompasses linguistic, metalinguistic, (and cognitive) factors.

a.)    Consider the metalinguistic aspects and stages of language learning: Identify the metalinguistic and linguistic aspects of AP tasks you are presenting to students (e.g., Schuele & Boudreau, 2008; van Kleeck, 1994; Wallach & Ocampo, 2022). 

b.)    Recognize the language knowledge, skills, and strategies that underlie

the academic tasks facing our students and recognize the differences among

knowledge, skills, and strategies (Ehren, 2000; 2013). Address how the gaps uncovered by tests and subtests used intersect with or reflect aspects of this triad of abilities.

c.)  Understand the interconnections and disconnecting among perceptual, cognitive, and linguistic elements of tasks.      

2.) Keep the inside and outside factors of processing in mind:

a.) Combine standardized instruments with observations of children and adolescents within the natural contexts (e.g., classrooms) in which they are having processing (and comprehension) difficulties

b.) Evaluate the changes in curricular and instructional demands throughout the

grades and observe how these changes affect what one “looks like” when processing/comprehending language (e.g., Ehren et al., 2014; Fang et al., 2014; Heller & Greenleaf, 2007).

3.)    Distinguish carefully between identifying children and adolescents who need help

(including referrals for special services) from “what we’re actually going to do with them.”

a.)    Recognize that identifying children who have bona fide auditory processing and/or language problems is different from creating and delivering meaningful intervention that connects to the “real world” (e.g., Lahey, 1990).

b.)     If auditory processing problems are identified, we may have to “get to them” through language (e.g., Kaderavek, 2011). Further, review the evidence suggesting that AP impairments may not be risk factors for speech, language, and other academic achievements (Hazan et al., 2009; Kamhi, 2011, 2014).

Specific Possibilities

            What are some steps one might take (or considerations one might entertain)

 when receiving a referral from a teacher, psychologist, or other team members that goes something like this:  “I think student X has an auditory processing problem.” Here are some questions one might ask to move beyond this terminology (from Wallach, 2020):

1.      Ask the teacher (or referral source) to describe in greater detail the behaviors that make him/her suspect APD. It would be helpful to obtain specific information about the materials used, instructions given, responses and work samples from the student to see if there’s “more than meets the ear.” Some auditory tasks are harder than they look on the surface (e.g., “auditory discrimination” tasks) (Troia, 2014).

2.      Try to determine the situations in which the student is having an “auditory” issue (and when he/she is not having an issue)

3.      Ask about the student’s READING level? Why? There is a strong reciprocity between spoken and written language systems. Stronger readers tend to perform better on certain “auditory” tasks.

4.      Address the COMPREHENSION ability of the student. Spoken and written comprehension are among the KEYS to understanding “auditory issues” especially the role of background knowledge (e.g., McKeown et al., 2009; Wallach & Ocampo, 2017).

In brief: Keep your eyes focused on how students function with “auditory” information in the real world in different situations. The more familiar a student is with what they are asked to process (the words, the topic, etc.) the “easier” it may be to process incoming auditory information.  Readers of this essay should think about their own experiences trying to process a foreign language they are less familiar with to get a sense of the interaction between language knowledge and auditory “correctness.




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