Speech and nonspeech: What are we talking about?

Abstract

Understanding of the behavioural, cognitive, and neural underpinnings of speech production is of interest theoretically, and is important for understanding disorders of speech production and how to assess and treat such disorders in the clinic. This paper addresses two claims about the neuromotor control of speech production: (1) speech is subserved by a distinct, specialised motor control system, (2) speech is holistic and cannot be decomposed into smaller primitives. Both claims have gained traction in recent literature, and are central to a task-dependent model of speech motor control (Ziegler, 2003a). The purpose of this paper is to stimulate thinking about speech production, its disorders, and the clinical implications of these claims. The paper poses several conceptual and empirical challenges for these claims – including the critical importance of defining speech. The emerging conclusion is that a task-dependent model is called into question as its two central claims are founded on ill-defined and inconsistently applied concepts. The paper concludes with discussion of methodological and clinical implications, including the potential utility of diadochokinetic (DDK) tasks in assessment of motor speech disorders and the contraindication of nonspeech oral motor exercises to improve speech function.

A survey of speech–language therapy provision for people with post‐stroke dysarthria in the UK

“…Given the ongoing debate regarding the precise role and efficacy of this approach (Mackenzie et al . , , Lof and Watson , Watson and Lof , Ziegler and Ackermann , Weismer ) it points to the importance of wider education and discussion (Maas ) in evidence based approaches in motor speech disorders.…”

The Radboud Dysarthria Assessment: Development and Clinimetric Evaluation

“…Recently, the German instrument Bogenhausen Dysarthria Scales (BoDys) has been published [33], which is also a fully perceptual assessment, but with 4 tasks to elicit connected speech only (conversational speech, sentence repetition, text reading, and picture story). Because this instrument is based on a different theoretical approach that strictly distinguishes speech motor control from the motor control of speechlike tasks [14], a direct comparison between the RDA and BoDys is not possible.…”

“…This requires the use of relevant speech tasks, of which spontaneous speech and reading are most functional and representative of daily life. There is a lively discussion about including maximum performance (speechlike) tasks in dysarthria assessment [14]. According to some authors, speech and speech-like tasks are controlled by separate motor control systems [15,16], whereas others believe that motor control of speech and speech-like tasks overlap or are, at least clinically, indistinguishable [14,17].…”

“…There is a lively discussion about including maximum performance (speechlike) tasks in dysarthria assessment [14]. According to some authors, speech and speech-like tasks are controlled by separate motor control systems [15,16], whereas others believe that motor control of speech and speech-like tasks overlap or are, at least clinically, indistinguishable [14,17]. We decided to include maximum performance tasks primarily to facilitate the interpretation of specific characteristics observed in spontaneous speech and reading, such as signs of hypotonia, hypertonia, hypokinesia, hyperkinesia, and ataxia.…”

Reference values of maximum performance tests of speech production

“…In addition, body height was registered because of its effect on lung capacity (Quanjer et al, 2012) and smoking habit and professional occupation because of their known effect on the quality of the voice (Awan & Alphonso, 2007;Timmermans et al, 2002). Based on profession, the level of vocal use was categorised by the classification of Koufman and Isaacson (1991): I: elite vocal performer (singers and actors), II: professional voice user (teachers, receptionists), III: non-vocal professionals (doctors, lawyers), and IV: non-vocal non-professionals (students, laborers).…”