Perceptual Processes Underlying Speech

Abstract

This study seeks to examine the role of perception in the acquisition and maintenance of speech and language. In particular, the influence of tactile kinaesthetic feedback is investigated with special reference to deviant acquisition of speech. The terms "speech" and "language" are often bracketed together in much of the literature, (Crystal 1973) thus underlining current views on their interrelationship in linguistic coding. For the purpose of clarification it is suggested that the following definitions will serve to differentiate the two aspects of communication. "Speech" is usually taken to refer to the specifically verbal component of human communication. As well as articulation it encompasses metalinguistic features of stress, intonation and rhythm. "Language" can be defined as an agreed system of arbitrarily determined symbols whereby human beings (or animals) are enabled to communicate one with another. Language extends beyond speech and is, of course, not necessarily verbal. Mime and gesture, for example, can on occasion prove to be entirely explicit. Reference has also been made to tactile kinaesthetic perception and this term (or simply kinaesthesis) is interchanged with the term proprioception in the work of many authorities (Annett 1967, Berry 1970, Brain 1963, Hebb 1972). In a personal communication, Jenkins (Professor of Oral Physiology, University of Newcastle upon Tyne) indicates that in fact the term kinaesthesis represents a more specific facet of proprioception, but that it is generally acceptable to use either form, The definition which is used throughout this text is that of Guyton(1972) viz. 'The conscious recognition of the orientation of the different parts of the body with respect to each other’. THE STUDY. An investigation of the speech and language skills of twenty children aged four through six years with repaired cleft lip and palate was carried out and their performance was compared with a group of subjects with normal oral structure. In addition, tactile kinaesthetic ability was investigated in both groups. The results of the study lead to the consideration of its implications in relation to a wider range of speech and language disorders (developmental dyspraxias and dysphasias). Some principles on which programmes of remediation might be based are discussed. This study was carried out mainly in the Birmingham Dental Hospital Children's Clinic and in the Orthodontic Clinic at the Corbett Hospital, Stourbridge. All the cleft palate children had originally undergone surgical treatment at the Regional Plastic Surgery Centre. Thus their medical and dental history was broadly similar. Although this background provided the source of the immediate study, the setting in fact ranges over a much wider area in terms of time and experience. Traditional emphasis on motor aspects of speech has for some time appeared to impose limitations on the efficacy of remedial programmes. The gradual acceptance and application of cybernetic principles to speech have brought about a recognition of the importance of sensori motor processes as essential concomitants of linguistic coding. With this reorientation of emphasis it is possible to find rational explanations for many of the symptoms of disordered language which have caused bewilderment and which hitherto have proved so intransigent to remediation. At the present time, knowledge of perceptual processes underlying speech is still no more than minimal and much investigation must continue. But as William James wrote, "Without continuing enquiry there is no progression." Enquiry will continue and one hopes that progress will be a result of this.