Introduction

Most children acquire language effortlessly during the early neurodevelopmental period. Analogously, language competence remains substantially stable throughout life in most individuals. However, language acquisition is anything but effortless for a significant number of kids, and an equally considerable number of individuals experience language disturbances in adulthood from traumatic injuries, vascular accidents, or neurodegenerative diseases. These burdensome conditions represent a fruitful and largely unexplored domain for the language sciences and, particularly, for a novel ‘dual-facing’ discipline called ‘clinical linguistics’ (henceforth, CL).

As formerly suggested by Cummings (2013), despite CL being commonly overlooked in the university syllabi, this branch of linguistic studies has the potential to provide groundbreaking advances at the theoretical and applied levels. In this regard, Jakobson (1968: 13) states, ‘[F]or the linguist, who is concerned with the fully developed structure of language, its acquisition and dissolution cannot fail to provide much that is instructive.’

In what follows, we will highlight the precise meaning of this term, the goals and the methodology of this relatively novel discipline and its theoretical implications and healthcare applications.

What is (and what is not) clinical linguistics?

The term ‘clinical linguistics’ made its first appearance in the 1970s but gained prominence thanks to David Crystal, who used it as the title of a very influential book—published in 1981—that outlined the epistemological status and the scope of this emerging field of research. The scholar gave voice to a plurality of experiences raised in the previous years and played a pivotal role in defining the novel discipline. According to him, ‘[c]linical linguistics is the application of linguistic science to the study of communication disability, as encountered in clinical situations’ (cf. Crystal, 1981: 1). More precisely, CL ‘is first and foremost a branch of applied linguistics’ (Crystal, 1984: 31), as it involves ‘the application of the theories, methods, and findings of linguistics (including phonetics) to the study of those situations where language handicaps are diagnosed and treated’ (Crystal, 1984: 30), regardless of the modality affected, i.e., spoken, written, or signed (Crystal, 1997).

Even though Crystal’s definition foresaw a one-way process, i.e., from linguistics to disordered speech/language, the possibility of using clinical data to inform linguistic theory became part of the research program from the very beginning (Ball & Kent, 1987).

CL sits at the intersection of several research areas. Its main focus is the verbal and gestural facets of language processing, but it also considers how these aspects interact with other cognitive and behavioral domains (Perkins & Howard, 2011): As most idiopathic and secondary communication disorders have been conceptualized as an emergent effect of complex interactions among genetic influences, environmental factors, and epigenetic effects (Kraft & De Thorne, 2014), the inherently multidisciplinary nature of CL is becoming increasingly evident (Perkins, 2011). Hence, it is also critical to shed light on the borders of the discipline by clarifying what falls outside its perimeter.

First, CL is the study of neither medical language (i.e., ‘medical linguistics,’ according to Orletti, Cardinaletti & Dovetto, 2015 and Stubington & Large, 2018) nor ‘medical humanities,’ which aims to investigate and improve the communication processes in the clinical domain, including but not limited to the specific terminology of medicine, doctor–patient interactions (e.g., plan of the diagnostic process, communication of a poor prognosis, and informed consent), and clinical information on drugs and health products (e.g., package leaflet).

Second, CL shares part of its methods and scope with psycho- and neurolinguistics but not its goals. Psycholinguistics focuses on exploring the mental aspects of language and speech (i.e., the cognitive architecture underlying the acquisition and usage of languages). In comparison, neurolinguistics is the study of these mental aspects’ neuroanatomical and neurofunctional correlates (i.e., how and where our brains store our knowledge of the language—or languages—that we speak, understand, read, and write; Ahlsén, 2006). Conversely, CL analyzes pathological verbalizations to i) profile language disorders, ii) improve the understanding of language functioning in neurotypical and atypical conditions, and ii) support clinicians in building linguistic tests and communication devices.

Last but not the least, clinical linguists must not improperly interfere with therapeutic activities: ‘While the linguistic features of these disorders are of inherent interest to clinical linguists, it is ultimately speech-language pathologists […] who must assess and treat clients with these disorders’ (Cummings, 2017).

A sketch of CL research subfields and methods

LC is rooted in structural and generative linguistics but, as already noticed by Perkins (2011: 922), has broadened and established deep relationships with many other research fields. Therefore, a clinical linguist should acquire knowledge of various medical disciplines such as neurology, otolaryngology/phoniatrics, psychiatry, and neuropsychology to be able to understand the primary scientific literature.

However, it is noteworthy to underline that, citing Cummings (2013: 10), ‘[t]he clinical linguist is, first and foremost, a linguist. As such, he comes to the study of language disorders with concepts, terminology, and methods which form part of the working knowledge of any academic linguist’.

Thus, LC usually investigates the ‘classical’ linguistic levels of analysis (i.e., phonetics, phonology, morphology, syntax, semantics, and pragmatics), on both productive and receptive sides.

As demonstrated by a vast number of handbooks, manuals, and scientific publications (e.g., Ball & Code, 1997; Ball & Lowrie, 2001; Ball, 2021), ‘clinical phonetics’ holds a special status compared to other branches. A wide range of communication disorders can disrupt speech in different ways: from developmental Speech and Sound Disorders to acquired neurogenic disorders (e.g., anarthria and dysarthria) and then fluency disorders, among several others. A proper description of these conditions and the planning of evidence-based treatment protocols need a solid grounding in articulatory, auditory, perceptual, and acoustical phonetics. Typical instrumentation includes, for example, electrolaryngography/electroglottography, electropalatography, sound spectrography, and pure tone/speech audiometry (Ball, 2021).

In recent years, new fields have been gaining increasing visibility. Among many others, we would like to point out ‘clinical pragmatics’ (Müller, 2000; Cummings, 2009; 2016), i.e., ‘the study of the various ways in which an individual’s use of language to achieve communicative purposes can be disrupted’ (Cummings, 2009: 6), and ‘clinical sociolinguistics’ (Ball, 2005), accounting for the impact of geographical, social, and situational variations on communication disorders.

As with other areas of language research, CL is not theory-neutral: Therefore, the reader should be aware that various approaches—both rationalist and empiricist (i.e., top-down and bottom-up strategies, respectively, McEnery & Wilson, 1996)—have been successfully applied in this domain. Let us mention some examples: Constraint-based nonlinear phonology has been employed since the 1980s for profiling and treating speech disorders (Spencer, 1984; Bernhardt & Stemberger, 2000; 2008), ‘optimality theory’ (Prince & Smolensky, 2004) has been used to explain children’s overgeneralization errors (Dinnsen & Gierut, 2008), and ‘articulatory phonology’ (Browman & Goldstein, 1986) has been exploited to investigate coordination issues in people with speech impairments (van Lieshout & Goldstein, 2008). However, while influential research has been carried out within the fold of the generative paradigm, it can be reasonably claimed—quoting Perkins (2011: 926)—that ‘[i]ts translation into effective tools for clinical practice has had limited success’ and ‘[m]any linguists who work on communication disorders feel that linguistic impairments (e.g., in specific language impairment and aphasia) cannot satisfactorily be accounted for in terms of a deficit in a language ‘module’.’

Theoretical implication and clinical applications

As stated before, CL is characterized by a two-way orientation: Its definition embraces the employment of clinical data to shed light upon theoretical issues in linguistics and the exploitation of linguistic analytic techniques to tackle clinical problems.

In fact, atypical verbal productions are inherently rule-governed: Therefore, the analysis of disordered speech and language—in particular, selective erosion patterns of communicative competence—can provide evidence for general theories of language functioning.

On the other hand, we can identify four main domains of application.

1. Creation of linguistic profiles, namely principled descriptions ‘[…] of just those features of a person’s (or group’s) use of language which will enable him to be identified for a specific purpose,’ i.e., in this case, ‘[…] to generate hypotheses concerning the nature of the disability and its remediation […]’ (Crystal, 1992: 1).

2. Building of linguistic resources (e.g., lexical databases) for clinical purposes.

3. Development of standardized evaluation tools to assess the communicative competence of the patients at various levels (i.e., phonological, morphological, syntactic, and pragmatic).

4. Design of assistive technologies and, in particular, augmentative and alternative communication (AAC) devices, such as voice output communication aids (VOCAs).

Future scenarios

Since the founding of the journal Clinical Linguistics and Phonetics in 1987 and the establishment of the International Clinical Phonetics and Linguistics Association (ICPLA) in 1991—i.e., the two main milestones for the development of CL worldwide—the scientific community has been constantly growing. In this ever-changing scenario, a key role will probably be played by Natural Language Processing (NLP) applications and speech technologies: We believe that, in the not-too-distant future, healthcare systems will take advantage of these cutting-edge methods (e.g., Digital Linguistic Biomarkers; Gagliardi et al., 2021) to better understand patients’ states, monitor disease trajectories, and provide appropriate treatments.

Acknowledgments

I am grateful to Professor Tommaso Raso for asking me to write this short article. I also thank Alice Suozzi for her critical reading of the text and insightful suggestions.

References

References books

Ball M.J., Perkins M.R., Müller N. & Howard S. (eds.) (2008). The Handbook of Clinical Linguistics. Malden (MA)-Oxford: Blackwell.

Cummings L. (2008). Clinical linguistics. Edinburgh: Edinburgh University Press.

Damico J.S., Nicole Müller N. & Ball M.J. (2010). The Handbook of Language and Speech Disorders. Hoboken (NJ): Wiley-Blackwell.

Müller N. & Ball M.J. (2013). Research Methods in Clinical Linguistics and Phonetics: A Practical Guide. Hoboken (NJ): Wiley-Blackwell.

Introductory Bibliography

Ahlsén E. (2006). Introduction to Neurolinguistics. Amsterdam-Philadelphia: John Benjamins.

Crystal D. (1981). Clinical Linguistics. Vienna: Springer Verlag.

Cummings L. (2013). Clinical linguistics: A primer. International Journal of Language Studies, 7(2): 1–30.

Cummings L. (2017). Clinical linguistics. In M. Aronoff (ed.), Oxford Research Encyclopedia of Linguistics, https://doi.org/10.1093/acrefore/9780199384655.013.337

De Saussure F. (1916), Cours de linguistique générale. Paris: Payot (English translation by Baskin W., 2011, Course in General Linguistics. New York: Columbia University press).

Perkins M.R. (2011). Clinical linguistics: Its past, present and future. Clinical Linguistics & Phonetics, 25(11–12): 922–927.

Advanced Bibliography

Ball M.J. (ed.) (2005). Clinical Sociolinguistics. Oxford: Blackwell

Ball M.J. (ed.) (2021). Manual of Clinical Phonetics. London: Routledge.

Ball M.J. & Code C. (ed.). (1997). Instrumental Clinical Phonetics. London: Whurr Publishers Ltd.

Ball M. J. & Kent R.D. (1987). Editorial. Clinical Linguistics and Phonetics, 1(1), 1–5.

Ball M.J. & Lowrie O.M. (eds.) (2001). Methods in Clinical Phonetics. London/Philadelphia: Whurr Publishers.

Bernhardt B.H. & Stemberger J.P. (2000). Workbook in Nonlinear Phonology for Clinical Application. Austin (TX): Pro-Ed.

Bernhardt B.H. & Stemberger J.P. (2008). Constraints-Based Nonlinear Phonological Theories: Application and Implications. In M.J. Ball et al. (eds.) The Handbook of Clinical Linguistics. Malden (MA)-Oxford: Blackwell, 467–479.

Browman C.P. & Goldstein L.M. (1986). Towards an articulatory phonology. Phonology Yearbook, 3, 219–52.

Crystal D. (1984). Linguistic Encounters with Language Handicap. Oxford: Blackwell.

Crystal D. (1992). Profiling Linguistic Disability. London: Edward Arnold.

Crystal D. (1997). The Cambridge Encyclopedia of Language. Cambridge: Cambridge University Press.

Cummings L. (2009). Clinical pragmatics. Cambridge: Cambridge University Press.

Cummings L. (ed.) (2016). Research in Clinical Pragmatics. Berlin: Springer.

Dinnsen D.A. & Gierut J.A. (2008). Optimality Theory: A Clinical Perspective. In M.J. Ball et al. (eds.) The Handbook of Clinical Linguistics. Malden (MA)-Oxford: Blackwell, 440–451.

Gagliardi G., Kokkinakis D. & Duñabeitia J.A. (2021) Editorial: Digital Linguistic Biomarkers: Beyond Paper and Pencil Tests. Frontiers in Psychology, 12:752238.

Jakobson R. (1941). Kindersprache, Aphasie und allgemeine Lautgesetz. Uppsala: Almqvist & Wiksell. (English translation, 1968, Child language, Aphasia, and Phonological Universal. The Hague/Paris/New York: Mouton Publishers).

Kraft S.J., DeThorne L.S. (2014). The Brave New World of Epigenetics: Embracing Complexity in the Study of Speech and Language Disorders. Current Developmental Disorders Reports, 1, 207–214.

McEnery T. & Wilson A. (2001). Corpus Linguistics. An Introduction. Edinburgh: Edinburgh University Press.

Müller N. (ed.) (2000). Pragmatics in speech and language pathology. Amsterdam-Philadelphia: John Benjamins.

Orletti F., Cardinaletti A. & Dovetto F.M. (2015). Tra linguistica medica e linguistica clinica. Il ruolo del linguista. Studi italiani di linguistica teorica e applicata, XLIV, 3: 392–394.

Perkins M.R. & Howard S. (2011). Clinical linguistics. In J. Simpson (ed.), The Routledge handbook of applied linguistics. New York: Routledge, 112–124.

Prince A. & Smolensky P. (2004). Optimality Theory: Constraint Interaction in Generative Grammar. Malden, (MA): Blackwell.

Spencer A. (1984). A nonlinear analysis of phonological disability. Journal of Communication Disorders, 17: 325–84.

Stubington T. & Large B. (2018). What’s in a name? A brief foray into the world of medical linguistics. British Journal of General Practice, 68(668): 137.

van Lieshout P.H.H.M. & Goldstein L.M. (2008). Articulatory Phonology and Speech Impairment. In M.J. Ball et al. (eds.) The Handbook of Clinical Linguistics. Malden (MA)-Oxford: Blackwell, 467–479.