New developments in EPG3 software

EPG research and therapy: further developments

Electropalatography (EPG) has been used in the past 50 years for studying the patterns of contact between the tongue and the palate during speech production in typical speakers and those with speech disorders due to different causes. At the 7th EPG Symposium in Japan that was held online on 24 January 2021 (see: https://epg-research.sakura.ne.jp/), a panel of invited experts discussed their views regarding further developments and application of the technique. This paper provides a summary of this discussion. EPG offers information on articulation which cannot be replaced by other instrumental measures of speech. Identified areas for further hardware development are thinner EPG plates, better dental and palatal coverage, wireless connectivity, and sensors that provide additional articulatory information (e.g. tongue pressure, tongue-palate distance). EPG can serve as a resource for teaching speech disorders and phonetics. Furthermore, EPG therapy can be combined with telepractice in the speech therapy of clients with speech disorders.

Super-imposing maxillary and palatal locations for electroarticulometry: A SIMPLE method

This study proposes a method of superimposing a physical palatal profile, extracted from a speaker's maxillary impression, onto real-time mid-sagittal articulatory data. A palatal/dental profile is first obtained by three-dimensional-scanning the maxillary impression of the speaker. Then a high resolution mid-sagittal palatal line, extracted from the profile, is sub-divided into articulatory zones and superimposed, by Iterative Closest Point algorithm, onto reconstructed palatal traces in electromagnetic articulometric (EMA) data. Evaluations were carried out by comparing consonant targets elicited by EMA with the proposed method and by static palatography. The proposed method yields accurate results, as supported by palatography.

Effectiveness of the Corrective Babbling Speech Treatment Program for Children with a History of Cleft Palate or Velopharyngeal Dysfunction

Objective

To investigate the effectiveness of a phonetic-based, parent-administered treatment to reduce cleft-related speech errors.

Design

Immediate treatment (IT) versus delayed treatment (DT) comparison followed by analysis of gains over approximately 4 months and again after a longer period of treatment for participants in both groups.

Participants

Thirteen participants with a history of cleft palate or velopharyngeal dysfunction and speech disorder.

Intervention

After training, parents were instructed to conduct daily 10-minute sessions of phonetic drills with their children.

Main Outcome Measures

Group differences in percent consonants correct (PCC) were compared between those who did and those who did not receive the treatment. Pre- and posttreatment PCC comparisons were made after approximately 4 months of treatment and after termination of treatment.

Results

Participants receiving Corrective Babbling therapy showed significant gains in PCC in limited contexts after 4 months of therapy. However, gains were not significantly greater for the IT versus DT group. Participants who continued with the treatment for longer than 4 months showed the greatest gains in PCC and had significant improvements in all speech contexts assessed. Parents reported satisfaction with the program.

Conclusions

The results of this study indicate that this treatment shows promise for at least some children with a history of cleft palate and velopharyngeal dysfunction.

Electropalatography in home training of retracted articulation in a Swedish child with cleft palate: effect on articulation pattern and speech

The aim was to evaluate the effectiveness of electropalatography (EPG) in home training of persistent articulation errors in an 11-year-old Swedish girl born with isolated cleft palate. The /t/ and /s/ sounds were trained in a single subject design across behaviours during an eight month period using a portable training unit (PTU). Both EPG analysis and perceptual analysis showed an improvement in the production of /t/ and /s/ in words and sentences after therapy. Analysis of tongue-contact patterns showed that the participant had more normal articulatory patterns of /t/ and /s/ after just 2 months (after approximately 8 hours of training) respectively. No statistically significant transfer by means of intelligibility in connected speech was found. The present results show that EPG home training can be a sufficient method for treating persistent speech disorders associated with cleft palate. Methods for transfer from function (articulation) to activity (intelligibility) need to be explored.

Electropalatographic (EPG) assessment of tongue-to-palate contacts in dysarthric speakers following TBI

The aim of the investigation was to compare EPG-derived spatial and timing measures between a group of 11 dysarthric individuals post-severe TBI and 10 age- and sex-matched neurologically non-impaired individuals. Participants of the TBI group were diagnosed with dysarthria ranging from mild-to-moderate-severe dysarthria. Each participant from the TBI and comparison group was fitted with a custom-made artificial acrylic palate that recorded lingual palatal contact during target consonant production in sentence- and syllable-repetition tasks at a habitual rate and loudness level. Analysis of temporal parameters between the comparison and TBI groups revealed prolonged durations of the various phases of consonant production, which were attributed to articulatory slowness, impaired speech motor control, impaired accuracy, and impaired coordination of articulatory movements in the dysarthric speakers post-TBI. For the spatial measurements, quantitative analysis, as well as visual inspection of the tongue-to-palate contact diagrams, indicated spatial aberrations in dysarthric speech post-TBI. Both the spatial and temporal aberrations may have at least partially caused the perceptual judgement of articulatory impairments in the dysarthric speakers.

Electropalatographic assessment of tongue-to-palate contact patterns and variability in children, adolescents, and adults

PURPOSE

To investigate the developmental time course of tongue-to-palate contact patterns during speech from childhood to adulthood using electropalatography (EPG) and a comprehensive profile of data analysis.

METHOD

Tongue-to-palate contacts were recorded during productions of /t/, /l/, /s/, and /k/ in 48 children, adolescents and adults (aged 6-38 years) using the Reading Electropalatograph system.

RESULTS

A protracted course of development for lingual control was indicated, with significant changes occurring until age 11 years; the adolescent period was in turn characterized by continual refinement of articulatory control. With maturity, a reduction in the amount of palatal contact and an anterior shift in the place of articulation was evident during anterior consonant productions, whereas the tongue-back-to-palate contact pattern became more consistent for the velar stop /k/.

CONCLUSION

These results support that maturation of the speech motor system is nonuniform.

Speech production in Parkinson's disease: I. An electropalatographic investigation of tongue-palate contact patterns

Previous studies have indicated that consonant imprecision in Parkinson's disease (PD) may result from a reduction in amplitude of lingual movements or articulatory undershoot. While this has been postulated, direct measurement of the tongue's contact with the hard palate during speech production has not been undertaken. Therefore, the present study aimed to use electropalatography (EPG) to determine the exact nature of tongue-palate contact in a group of individuals with PD and consonant imprecision (n = 9). Furthermore, the current investigation also aimed to compare the results of the participants with PD to a group of aged (n = 7) and young (n = 8) control speakers to determine the relative contribution of ageing of the lingual musculature to any articulatory deficits noted. Participants were required to read aloud the phrase 'I saw a _ today' with the artificial palate in-situ. Target words included the consonants /l/, /s/ and /t/ in initial position in both the /i/ and /a/ vowel environments. Phonetic transcription of phoneme productions and description of error types was completed. Furthermore, representative frames of contact were employed to describe the features of tongue-palate contact and to calculate spatial palatal indices. Results of the perceptual investigation revealed that perceived undershooting of articulatory targets distinguished the participant group with PD from the control groups. However, objective EPG assessment indicated that undershooting of the target consonant was not the cause of the perceived articulatory errors. It is, therefore, possible that reduced pressure of tongue contact with the hard palate, sub-lingual deficits or impaired articulatory timing resulted in the perceived undershooting of the target consonants.

Advances in EPG for treatment and research: an illustrative case study

Electropalatography (EPG), a technique which reveals tongue-palate contact patterns over time, is a highly effective tool for speech research. We report here on recent developments by Articulate Instruments Ltd. These include hardware for Windows-based computers, backwardly compatible (with Reading EPG3) software systems for clinical intervention and laboratory-based analysis for EPG and acoustic data, and an enhanced clinical interface with client and file management tools. We focus here on a single case study of a child aged 10+/-years who had been diagnosed with an intractable speech disorder possibly resulting ultimately from a complete cleft of hard and soft palate. We illustrate how assessment, diagnosis and treatment of the intractable speech disorder are undertaken using this new generation of instrumental phonetic support. We also look forward to future developments in articulatory phonetics that will link EPG with ultrasound for research and clinical communities.

Tongue-to-palate contact patterns and variability of four English consonants in an /i/ vowel environment

Minimal data exist describing tongue-to-palate contact patterns and their variability in normal speakers of English. Consequently, the aims of the present study were to examine, using a comprehensive profile of data analysis, tongue-to-palate contact patterns and their variability in a group of ten normal speakers of English using the Reading Electropalatography3 (EPG3) system. Each speaker produced ten repetitions of the target words tea, leap, sea, and key following the carrier phrase 'I saw a ...'. Results revealed that the contact patterns produced exhibited similar characteristics to those described in earlier research. Additionally, the lateral approximant /i/ exhibited the highest degree of intra-subject variability with the alveolar fricative /s/ exhibiting the least. The results of this study are discussed in relation to existing normative data.

Electropalatography and the Linguagraph system

This paper describes the technique of electropalatography and the development of Linguagraph, which is a user-friendly, clinical instrument, for measurement of tongue/palate contact, during speech. Linguagraph allows objective assessment of tongue function; appropriate targeting of therapy is therefore possible. Visual feedback is also provided, for therapy, and an objective measurement of outcome is easily obtained. Linguagraph was used, for both therapy and assessment, in a clinical trial. Technical aspects of Linguagraph and of the trial results are presented here. These suggest that the instrument will prove useful in the assessment and management of many speech disorders. Full clinical details of the trial are reported elsewhere.