Fiona Gibbon

Visual display of tongue-palate contact: Electropalatography in the assessment and remediation of speech disorders

The technique of electropalatography (EPG) records the location and timing of tongue contacts with the hard palate during continuous speech. Recent developments in hardware and software design of the Reading electropalatograph are described and applications of the technique in assessment and remediation of a variety of speech disorders are outlined. In assessment, it is shown that EPG can provide insights into possible origins of auditorily perceived errors, and case descriptions illustrate how this information can lead to a more rationalised approach to treatment. In therapy, the provision of real-time visual feedback of tongue movement can be effective in the remediation of certain types of intractable speech problems. Finally, the importance of techniques such as EPG in the objective evaluation of treatment procedures is discussed in the light of the increasing demand for accountability within the speech therapy service.

Prosody and its relationship to language in school-aged children with high-functioning autism

BACKGROUND Disordered expressive prosody is a widely reported characteristic of individuals with autism. Despite this, it has received little attention in the literature and the few studies that have addressed it have not described its relationship to other aspects of communication. AIMS To determine the nature and relationship of expressive and receptive language, phonology, pragmatics, and non-verbal ability in school-aged children with high-functioning autism and to determine how prosody relates to these abilities and which aspects of prosody are most affected. METHODS & PROCEDURES A total of 31 children with high-functioning autism and 72 typically developing children matched for verbal mental age completed a battery of speech, language, and non-verbal assessments and a procedure for assessing receptive and expressive prosody. OUTCOMES & RESULTS Language skills varied, but the majority of children with high-functioning autism had deficits in at least one aspect of language with expressive language most severely impaired. All of the children with high-functioning autism had difficulty with at least one aspect of prosody and prosodic ability correlated highly with expressive and receptive language. The children with high-functioning autism showed significantly poorer prosodic skills than the control group, even after adjusting for verbal mental age. CONCLUSIONS Investigating prosody and its relationship to language in autism is clinically important because expressive prosodic disorders add an additional social and communication barrier for these children and problems are often life-long even when other areas of language improve. Furthermore, a receptive prosodic impairment may have implications not only for understanding the many functions of prosody but also for general language comprehension.

Abnormal Patterns of Tongue-Palate Contact in the Speech of Individuals with Cleft Palate.

Individuals with cleft palate, even those with adequate velopharyngeal function, are at high risk for disordered lingual articulation. This article attempts to summarize current knowledge of abnormal tongue‐palate contact patterns derived from electropalatographic (EPG) data in speakers with cleft palate. These data, which have been reported in 23 articles published over the past 20 years, have added significantly to our knowledge about cleft palate speech. Eight abnormal patterns of tongue‐palate contact are described and illustrated with data from children and adults with repaired cleft palate. The paper also discusses some of the problems in interpreting EPG data from speakers with abnormal craniofacial anatomy and emphasizes the importance of quantifying relevant aspects of tongue‐palate contact data. Areas of research requiring further investigation are outlined.

Temporal and spatial aspects of lingual coarticulation in /kl/ sequences: a cross-linguistic investigation.

Temporal and spatial aspects of lingual coarticulation in /kl/ clusters in intervocalic position (VklV) were investigated in six European languages: Catalan, English, French, German, Italian, and Swedish. Three speakers of each language repeated a set of real words and nonsense items five times. Temporal overlap of /k/ and /l/ gestures, as represented by a numerical “overlap index”, was interpreted as tongue-tip/tongue-body coarticulation, and was measured from electropalatographic and airflow records. Results revealed several language-specific features. For example, the tendency to overlap was different for the six languages. All the languages except Swedish showed some instances of overlap, and Catalan showed the strongest tendency. The vowel environment also had a significant effect: The presence of an open back vowel in V1 and V2 positions increased the tendency for overlap to occur. However, there was no statistically significant difference in overlap between nonsense and real words. Spatial information from EPG data showed that articulatory placement of the tongue-body gesture was more retracted in a /kl/ cluster compared to a singleton consonant. All the languages under investigation showed this phenomenon. These findings are discussed in terms of possible constraints operating between the tip/blade and tongue-body systems.

An electropalatographic investigation of Middorsum palatal stops in an adult with repaired cleft palate

OBJECTIVE Middorsum palatal stops are compensatory articulations that occur relatively frequently in cleft palate speech. This study used electropalatographic (EPG) and acoustic data to investigate /t/ and /k/ targets produced as middorsum palatal stops ([c]) by an adult with an articulation disorder associated with a repaired cleft palate. RESULTS Two novel observations were made from the instrumental data. First, although /t/ and /k/ targets were judged by phonetically trained listeners as homophonous (i.e., both produced as [c]), the EPG data revealed that the place of articulation for the [c] produced for /t/ was more anterior than the place of articulation for the [c] produced for /k/. Second, production of palatal stops involved lateral release followed by a variable period of lateral friction. Measurements made from the instrumental data quantified the temporal extent of lateral friction during the aspiration period. CONCLUSIONS These observations merit further systematic investigation in cleft palate speech, and the procedures reported in this study are considered appropriate for such future research.

Articulatory description and treatment of “lateral /s/” using electropalatography: a case study

Cases of so-called “lateral /s/” articulation are frequently encountered in the clinic but are difficult to treat using conventional therapy. In this study, the technique of electropalatography (EPG) is used on a 12 year old with a lateral /s/ as a therapeutic tool providing a real-time visual feedback display of tongue contacts with the palate during speech. EPG provided detailed articulatory information, unavailable from an auditory-based analysis, which could be incorporated into the therapy programme. A normal /s/ pattern was achieved in connected speech after only four clinical sessions, and was maintained when reassessed after six months.

The application of electropalatography (EPG) to the remediation of speech disorders in school-aged children and young adults

Electropalatography (EPG) is one of a number of computer-based biofeedback techniques being applied increasingly and apparently successfully to the treatment of speech pathologies. This paper briefly examines the function of such biofeedback systems within the remediation process and looks in particular at the features of the EPG system which render it a useful therapeutic tool. Details are summarised of a project initiated to evaluate the use of EPG in the management of a large group of speech-disordered children and young adults. Successful applications of the technique are presented by examining the different types of motor speech skill which subjects acquired during intervention. These are summarised as the establishment of completely new articulatory patterns, the inhibition of abnormal lingual patterns, and the modification of temporal or spatial aspects of one or several existing patterns. Possible reasons for the success of EPG as a therapeutic technique, and issues concerning subject selection, are discussed.

Changes in linguapalatal contact patterns during therapy for velar fronting in a 10‐year‐old with Down's syndrome

BACKGROUND Articulation errors in the speech of people with Downs syndrome are frequent and often resistant to speech therapy. This preliminary study investigates the use of electropalatography (EPG) to diagnose and treat abnormal articulation patterns associated with velar fronting in a 10-year-old girl. AIMS The study measured changes in the accuracy and stability of linguapalatal (tongue-palate) contact patterns during a 14-week course of visual feedback therapy using EPG. Therapy aimed to resolve a pattern of velar fronting whereby targets /k, g, eta/ had alveolar placement [t, d, n]. METHODS & PROCEDURES The participant was a girl (P) with Downs syndrome aged 10;11 years. P had a moderate-severe speech disorder, which included velar fronting. Her speech was recorded with EPG on three occasions during a 14-week course of therapy: first, before therapy; second, midway through therapy; and third, after therapy. Three analyses were conducted on the EPG data. The first used an EPG classification scheme that identified accuracy of placement for /t/ and /k/ targets. The second was a centre of gravity measure that detected whether P produced a significant difference between /t/ and /k/ targets. The third was a variability index that quantified the stability of contact patterns. OUTCOMES & RESULTS The results of the EPG classification showed that before therapy, /t/ and /k/ targets had identical alveolar placement, reflecting the process of velar fronting. The results after therapy showed that 87% of /k/ targets had accurate velar placement. The centre of gravity measure showed no difference in contact patterns for /t/ and /k/ before therapy, but a statistically significant difference at the second and third recordings. The variability index showed stable contact patterns before therapy for /t/ and /k/ targets, but both became highly unstable midway through therapy, with a return to stability at the third recording. We embed a discussion of Ps increased articulation instability during therapy in a recent theoretical framework--dynamic systems--that attempts to account for the emergence of new behavioural forms. CONCLUSIONS These preliminary results suggest that EPG has potential as an effective diagnostic and therapy procedure for articulation errors in people with Downs syndrome. A major issue still to be addressed, however, is the extent to which others will benefit from this approach to intervention.

Phonetic and phonological errors in children with high functioning autism and Asperger syndrome

This study involved a qualitative analysis of speech errors in children with autism spectrum disorders (ASDs). Participants were 69 children aged 5–13 years; 30 had high functioning autism and 39 had Asperger syndrome. On a standardized test of articulation, the minority (12%) of participants presented with standard scores below the normal range, indicating a speech delay/disorder. Although all the other children had standard scores within the normal range, a sizeable proportion (33% of those with normal standard scores) presented with a small number of errors. Overall 41% of the group produced at least some speech errors. The speech of children with ASD was characterized by mainly developmental phonological processes (gliding, cluster reduction and final consonant deletion most frequently), but non-developmental error types (such as phoneme specific nasal emission and initial consonant deletion) were found both in children identified as performing below the normal range in the standardized speech test and in those who performed within the normal range. Non-developmental distortions occurred relatively frequently in the children with ASD and previous studies of adolescents and adults with ASDs shows similar errors, suggesting that they do not resolve over time. Whether or not speech disorders are related specifically to ASD, their presence adds an additional communication and social barrier and should be diagnosed and treated as early as possible in individual children.

Widening Access to Electropalatography for Children With Persistent Sound System Disorders

Previous studies have demonstrated the value of using electropalatography (EPG) to assess, diagnose, and treat persistent sound system disorders in children. However, the application of EPG researc...