Browsing by Person "Wrench, Alan A."

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A common co-ordinate system for mid-sagittal articulatory measurement
(2011-06) Scobbie, James M.; Lawson, Eleanor; Cowen, Steve; Cleland, Joanne; Wrench, Alan A.
A standard practice in EMA articulatory measurement is to set the origin of the measurement space near the boundary of the upper incisors and gum, on a standard reference coil. A conventional horizontal dimension is defined as being parallel to the speaker's unique bite (occlusal) plane. We propose that this convention be extended to other instrumentation, with a focus on how it can be achieved for ultrasound tongue imaging (UTI) in particular, using a disposable and hygienic vacuum-formed bite plate of known size. A bite plane trace, like a palate trace, provides a consistent reference to allow images to be rotated and translated in case the probe is in a new location relative to a speaker's cranial space. The bite plane also allows speakers with differently shaped palates to be overlaid, and for ultrasound data to share a coordinate space with EMA. We illustrate the proposal using a sample of six speakers. The average bite plane slope could be used to retrospectively rotate ultrasound data that lacks bite-plane measurement
A Multi-Channel/Multi-Speaker Articulatory Database for Continuous Speech Recognition Research.
(2000) Wrench, Alan A.
The goal of this research is to improve the performance of a speaker-independent Automatic Speech Recognition (ASR) system by using directly measured articulatory parameters in the training phase. This paper examines the need for a multi-channel/multi-speaker articulatory database and describes the design of such a database and the processes involved in its creation.
A new EPG protocol for assessing DDK accuracy scores in children : a Down's syndrome study
(2007-08) McCann, Joanne; Wrench, Alan A.; This research was supported by a grant form the
Recent research has suggested that eliciting diadochokinetic (DDK) rate and accuracy in young children is difficult [1], with analysis being timeconsuming.This paper details a new protocol for assessing DDK in young children or children with intellectual impairment (Down's syndrome) and a method for calculating accuracy scores automatically. Accuracy scores were calculated from auditory and electropalatographic analyses and found to correlate in some instances. The children with Down's syndrome presented with similar DDK rates to typically-developing children but reduced accuracy.
Acoustic analysis of /l/ in glossectomees
(1998) Lunn, J.; Wrench, Alan A.; Beck, Janet M.
The production of /l/ is examined for pre- and post-operative patients who have undergone surgery in three distinct areas (anterior, posterior or lateral tongue) followed by radiotherapy and reconstruction. Results show F1 and F2 to be raised after surgery in all cases. Normalised measures of tongue height (F1-F0) and extension (F2-F1) revealed no significant change after surgery to the side of the tongue but in the other two categories, results indicated a change normally associated with both raising and fronting of the tongue. The paper compares these results with findings from other studies and considers possible mechanisms for the observed changes. 1. INTRODUCTION Previous work [1] by the authors has focused on the production of /s/ and /sh/ in pre- and postoperative glossectomee speech. Although, these phonemes can be objectively shown to be affected by surgery, change in dentition also plays a critical role and in a large number of cases speech therapy must wait until new dentu...
Advances in EPG for treatment and research: an illustrative case study
(Taylor & Francis, 2004) Scobbie, James M.; Wood, Sara; Wrench, Alan A.
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. Keywords: Electropalatography, ultrasound, speech disorders, perceptual analysis
Advances in EPG palate design.
(Taylor & Francis, 2007) Wrench, Alan A.
Electropalatography (EPG) is a highly effective tool for speech research and for the diagnosis and treatment of a range of speech disorders. The technique requires an EPG palate to be custom made for each user. The manufacture of the palate is both costly and time consuming and inhibits wider uptake of the technique. This paper undertakes a thorough reexamination of all aspects of EPG palate design including criteria for selecting the number and location of contacts, materials properties, costs and safety issues. Palate design over the last 30 years is reviewed and a new design (the Articulate palate) is proposed based on the findings, which minimizes cost while maximizing comfort, safety, convenience, reliability and accuracy.
An articulatory investigation of word final /l/ and /l/-sandhi in three dialects of English.
(Universitat Autnoma de Barcelona, 2003) Scobbie, James M.; Wrench, Alan A.; Recasens, D.; Romero, J.; SolÃ©, M. J.
We use the MOCHA articulatory speech database to ex-plore word-final /l/ in English. Eight speakers, drawn from three nations with distinct phonological systems (Scotland, England and USA) all display pervasive and systematic /l/ vocalisation (defined as lack of alveolar contact in EPG data). Vocalisation of word-final /l/ is radically con-text-dependent for seven subjects. These English speakers have a post-lexical external sandhi alternation of conso-nantal vs. vocalic /l/ which appears categorical. We de-scribe the general tendencies and the systematic linguistic differences between speakers, which are orthogonal to national dialect. Coda (re)syllabification of /l/ is not subtle or flexible enough to condition the distribution of vocali-sation. Prosodic, segmental and phrasal factors are all re-quired. A preliminary EMA analysis of intracontextual variability reveals both gradient and categorical aspects.
An EPG therapy protocol for remediation and assessment of articulation disorders.
(ICSLP, 2002) Wrench, Alan A.; Gibbon, Fiona; McNeill, Alison M.; Wood, Sara; Hansen, John H.L.; Pellom, Bryan
This paper describes technical and methodological advances in the development of a procedure for measuring changes in accuracy and stability of linguapalatal (tongue-palate) contact patterns during a course of visual feedback therapy using electropalatography (EPG). The procedure is exemplified by a case in which therapy was aimed at resolving a pattern of velar fronting whereby phonetic targets /k, g,
An investigation of sagittal velar movement and its correlation with lip, tongue, and jaw movement.
(1999) Wrench, Alan A.
This paper examines the correlation between velar movement and the movement of other articulators in the midsagittal plane. A physiological model is proposed, which, while being based on common knowledge, is more extensive than has been used explicitly to explain observed movements of the velum. The model is used to guide the measurements taken from raw articulatory data provided by Electromagnetic Articulograph (EMA). The midsagittal velar movement is then examined for four different sentences by separate speakers and attempts are made to explain the patterns by reference to the model. The data was taken from a database of between 220 and 460 phonetically balanced sentences per speaker. This type of dataset allow general patterns of behavior to be uncovered. One such observation made and discussed in this paper is velum lowering before oral velar stops.
An ultrasound protocol for comparing tongue contours: upright vs. supine
(2011-08) Wrench, Alan A.; Cleland, Joanne; Scobbie, James M.; EPSRC EP/I027696/1
A study is described that employs ultrasound to measure the effects of gravity on production of vowels. The materials are designed to encourage consistent production over repetitions. A recording and analysis protocol is described which allows for correction for probe movement or rejection of data where correction is not possible. Results indicate a slight superior and posterior displacement of the tongue root in supine posture, consistent with a shift in the support structure of the tongue.
The application of Ultrasound Evaluation of Swallowing (USES) to the analysis of hyoid kinematics in healthy swallows
(American Speech-Language-Hearing Association, 2025-04-07) Ma, Joan K-Y; Wrench, Alan A.
Purpose: Using ultrasound as an adjunct tool for swallowing assessment has gained significant momentum in recent years, with research gaps in areas such as speech and language therapist–driven protocol and measurement methods. This study outlines the recording protocol of Ultrasound Evaluation of Swallowing (USES). Additionally, a set of multidimensional measurements capturing the hyoid kinematics in typical swallows was compared with previous studies to evaluate the current protocol and to develop an ultrasound database of healthy swallows to further the clinical implementation of USES. Method: Swallowing data were acquired from 41 healthy participants. Both discrete swallows (5- and 10-ml) and continuous swallows (100-ml) were analyzed. Automatic tracking of the hyoid and mandible positions using a deep neural net was applied. Six swallowing events of interest were identified for each swallow (beginning hyoid position, maximal hyoid position, hyoid advancement, hyoid retraction, peak forward velocity, and peak backward velocity), and a series of hyoid parameters characterizing the amplitude, velocity, and timing of the movement were calculated and compared across different types of swallows. Results: Results showed significant differences between continuous and discrete swallows. Continuous swallows were characterized by shorter maximal hyoid displacement, a shorter duration between the start of the swallow and the maximal displacement, a shorter total swallow duration, and lower peak velocity in both forward and backward hyoid movement. No significant difference was observed between the 5- and 10-ml swallows in hyoid movement amplitude, velocity, or duration. Conclusions: The quantification of hyoid kinematics in swallowing through the current USES recording protocol, combined with the semi-automatic extraction of hyoid function by applying a deep neural net and feature-finding algorithms, provides initial evidence to support its clinical utility in swallowing assessment. Further studies, including those of different clinical populations, to evaluate the sensitivity of the hyoid metrics in detecting changes to swallowing would support the clinical translation.
Articulatory characteristics of the occlusion phase of /t / compared to /t/ in adult speech
(Taylor & Francis, 2007-03) Liker, Marko; Gibbon, Fiona; Wrench, Alan A.; Horga, Damir
This study used electropalatography (EPG) to investigate articulatory characteristics of /t / and /t/ occlusion in order to provide normative data to be used for the diagnosis and treatment of individuals with speech disorders. EPG data from the EUR-ACCOR database were analysed for nonsense VCV sequences containing /t / and /t/ in nine vowel contexts for seven English speaking adults. The main results of this study are that all speakers had a significantly more posterior placement for /t / compared to /t/ and that placement was stable during the occlusion phase of both /t / and /t/. For most speakers, the occlusion phase was longer for /t / compared to /t/, the occlusion phase generally involved more EPG contact and was slightly more variable in /t / compared to /t/, but these differences were not statistically significant for all speakers. The implications of the results for diagnosing and treating speech disorders are discussed.
Articulatory, acoustic and perceptual aspects of fricative/stop coarticulation
(1998) Nguyen, Noel; Wrench, Alan A.; Gibbon, Fiona; Hardcastle, William J.
Automated assessment of hyoid movement during normal swallow using ultrasound
(Royal College of Speech and Language Therapists, 2022-03-14) Ma, Joan K-Y; Wrench, Alan A.
Background The potential for using ultrasound by speech and language therapists (SLTs) as an adjunct clinical tool to assess swallowing function has received increased attention during the COVID-19 pandemic, with a recent review highlighting the need for further research on normative data, objective measurement, elicitation protocol and training. The dynamic movement of the hyoid, visible in ultrasound, is crucial in facilitating bolus transition and protection of the airway during a swallow and has shown promise as a biomarker of swallowing function.
Beyond the edge: Markerless pose estimation of speech articulators from ultrasound and camera images using DeepLabCut
(MDPI, 2022-02-02) Wrench, Alan A.; Balch-Tomes, Jonathan
Automatic feature extraction from images of speech articulators is currently achieved by detecting edges. Here, we investigate the use of pose estimation deep neural nets with transfer learning to perform markerless estimation of speech articulator keypoints using only a few hundred hand-labelled images as training input. Midsagittal ultrasound images of the tongue, jaw, and hyoid and camera images of the lips were hand-labelled with keypoints, trained using DeepLabCut and evaluated on unseen speakers and systems. Tongue surface contours interpolated from estimated and hand-labelled keypoints produced an average mean sum of distances (MSD) of 0.93, s.d. 0.46 mm, compared with 0.96, s.d. 0.39 mm, for two human labellers, and 2.3, s.d. 1.5 mm, for the best performing edge detection algorithm. A pilot set of simultaneous electromagnetic articulography (EMA) and ultrasound recordings demonstrated partial correlation among three physical sensor positions and the corresponding estimated keypoints and requires further investigation. The accuracy of the estimating lip aperture from a camera video was high, with a mean MSD of 0.70, s.d. 0.56, mm compared with 0.57, s.d. 0.48 mm for two human labellers. DeepLabCut was found to be a fast, accurate and fully automatic method of providing unique kinematic data for tongue, hyoid, jaw, and lips.
Categorising vocalisation of English /l/ using EPG, EMA and ultrasound.
(2003) Wrench, Alan A.; Scobbie, James M.
ABSTRACT: We consider allophonic and speaker-specific variation in the alveolar gestures found in vocalised and consonantal /l/. EMA or ultrasound give tongue position data and EPG gives simultaneous alveolar contact data. We find systematic vocalisation with interspeaker variation in the prosodic distribution of these vocalised forms. The data suggest some allophonic variation is subtle, continuous and gradient, while some is more categorical.
Comparing articulatory images: An MRI / Ultrasound Tongue Image database
(ISSP, 2011-06) Cleland, Joanne; Wrench, Alan A.; Scobbie, James M.; Semple, Scott; EPSRC EP/I027696/1
We report the development of a database that will contain paired ultrasound and MRI of tongue movements and shapes from 12 adults, illustrated with pilot data from one speaker. The primary purpose of the database will be to evaluate the informational content of ultrasound tongue images on the basis of the richer articulatory structures visible with MRI, and to provide tongue shape information that can later be incorporated into an image processing algorithm to enhance ultrasound tongue images. Ultrasound is an increasingly popular technique for studying speech production since it provides a real-time image of tongue movements. Its potential as a visualfeedback speech therapy tool has been recognised but has not yet been exploited to any great extent. In part this is because obstruents like /t/ /k/ /ch/,which are important targets for therapy, have tongue shapes in both canonical and common error productions which ultrasound displays rather poorly compared to the more easily-imaged vowels, glides and liquids. By enhancing ultrasound images in real time with information based on our corpus, we aim to create images which we hypothesise will A) be more easily understood by children for clinical feedback B) extend the range and utility of ultrasound generally.
The Compartmental Tongue
(American Speech-Language-Hearing Association, 2024-07-03) Wrench, Alan A.
Purpose: Tongue anatomy and function is widely described as consisting of four extrinsic muscles to control position and four intrinsic muscles to control shape. This myoarchitecture cannot, however, explain independent tongue body and blade movement nor accurately model the subtlety of observed lingual shapes. This study presents the case for a finer neuromuscular structure and functional description. Method: Using the theoretical framework of the partitioning hypothesis, evidence for neuromuscular compartments of each of the lingual muscles was discerned by reviewing studies of lingual anatomy, hypoglossal nerve staining, hypoglossal motoneuron axon tracing, muscle fiber type distribution, and electromyography. Muscle fibers of the visible human female were manually traced to produce a three-dimensional atlas of muscular compartments. A kinematic study was undertaken to determine the degree of independent movement between different parts of the tongue. A simple biomechanical model was used to demonstrate how synergistic groups of compartments can control sectors of the tongue. Results: Results indicated as many as 10 compartments of genioglossus, two each of superior and inferior longitudinal, eight of styloglossus, three of hyoglossus, and six each of transversus and verticalis, while palatoglossus may not have a significant role in tongue function. Kinematic analysis indicated independent control of five sectors of the tongue body, and biomechanical modeling demonstrated how this control may be achieved. Conclusion: Evidence is presented for a lingual structure based on neuromuscular compartments, which work together to position and shape sectors of the tongue and independently control tongue body and blade.
Conditioning factors in external sandhi : an EPG study of English /l/ vocalisation.
(2007-08) Scobbie, James M.; Pouplier, Marianne; Wrench, Alan A.; Acknowledgements. Research infrastructure development
English l-sandhi involves an allophonic alternation in alveolar contact for word-final /l/ in connected speech [4]. EPG data for five Scottish Standard English and five Southern Standard British English speakers shows that there is individual and dialectal variation in contact patterns. We analysed vocalisation rate (% of tokens with no alveolar contact) and the area of any residual alveolar contact. Word-final /l/ contact is, to some extent, onset-like before vowel-initial words and coda-like before words with a labial onset C. If the vowel has a glottal attack, however, or the onset C is /h/, sandhi is less predictable, suggesting that resyllabification is insufficient as a mechanism for conditioning tongue tip behaviour of word final /l/.
Continuous speech recognition using articulatory data.
(2000) Wrench, Alan A.; Richmond, Korin
In this paper we show that there is measurable information in the articulatory system which can help to disambiguate the acoustic signal. We measure directly the movement of the lips, tongue, jaw, velum and larynx and parameterise this articulatory feature space using principal components analysis. The parameterisation is developed and evaluated using a speaker dependent phone recognition task on a specially recorded TIMIT corpus of 460 sentences. The results show that there is useful supplementary information contained in the articulatory data which yields a small but significant improvement in phone recognition accuracy of 2%. However, preliminary attempts to estimate the articulatory data from the acoustic signal and use this to supplement the acoustic input have not yielded any significant improvement in phone accuracy.