MEASURING PRE-SPEECH ARTICULATION

Abstract: What do speakers do when they start to talk? This thesis concentrates on the articulatory aspects of this problem, and offers methodological and experimental results on tongue movement, captured using Ultrasound Tongue Imaging (UTI). Speech initiation occurs at the start of every utterance. An understanding of the timing relationship between articulatory initiation (which occurs first) and acoustic initiation (that is, the start of audible speech) has implications for speech production theories, the methodological design and interpretation of speech production experiments, and clinical studies of speech production. Two novel automated techniques for detecting articulatory onsets in UTI data were developed based on Euclidean distance. The methods are verified against manually annotated data. The latter technique is based on a novel way of identifying the region of the tongue that is first to initiate movement. Data from three speech production experiments are analysed in this thesis. The first experiment is picture naming recorded with UTI and is used to explore behavioural variation at the beginning of an utterance, and to test and develop analysis tools for articulatory data. The second experiment also uses UTI recordings, but it is specifically designed to exclude any pre-speech movements of the articulators which are not directly related to the linguistic content of the utterance itself (that is, which are not expected to be present in every full repetition of the utterance), in order to study undisturbed speech initiation. The materials systematically varied the phonetic onsets of the monosyllabic target words, and the vowel nucleus. They also provided an acoustic measure of the duration of the syllable rhyme. Statistical models analysed the timing relationships of articulatory onset, and acoustic durations of the sound segments, and the acoustic duration of the rhyme. Finally, to test a discrepancy between the results of the second UTI experiment and findings in the literature, based on data recorded with Electromagnetic Articulography (EMA), a third experiment measured a single speaker using both methods and matched materials. Using the global Pixel Difference and Scanline-based Pixel Difference analysis methods developed and verified in the first half of the thesis, the main experimental findings were as follows. First, pre-utterance silent articulation is timed in inverse correlation with the acoustic duration of the onset consonant and in positive correlation with the acoustic rhyme of the first word. Because of the latter correlation, it should be considered part of the first word. Second, comparison of UTI and EMA failed to replicate the discrepancy. Instead, EMA was found to produce longer reaction times independent of utterance type.Keywords: Speech initiation, pre-speech articulation, delayed naming, ultrasound tongue imaging, electromagnetic articulography, automated methods

Perustaajuusjakaumien vertaileminen Praatilla ja R:llä

Pitch analysis tools are used widely in order to measure and to visualize the melodic aspects of speech. The resulting pitch contours can serve various research interests linked with speech prosody, such as intonational phonology, interaction in conversation, emotion analysis, language learning and singing. Due to physiological differences and individual habits, speakers tend to differ in their typical pitch ranges. As a consequence, pitch analysis results are not always easy to interpret and to compare among speakers. In this study, we use the Praat program (Boersma & Weenink 2015) for analyzing pitch in samples of conversational Finnish speech and we use the R statistical programming environment (R Core Team, 2014) for further analysis and visualization. We first describe the general shapes of the speaker-specific pitch distributions and see whether and how the distributions vary between individuals. A bootstrapping method is applied to discover the minimal amount of speech that is necessary in order to reliably determine the pitch mean, median and mode for an individual speaker. The scripts and code written for the Praat program and for the R statistical programming environment are made available under an open license for experimenting with other speech samples. The datasets produced with the Praat script will also be made available for further studies.Peer reviewe

Comparing pitch distributions using Praat and R

Pitch analysis tools are used widely in order to measure and to visualize the melodic aspects of speech. The resulting pitch contours can serve various research interests linked with speech prosody, such as intonational phonology, interaction in conversation, emotion analysis, language learning and singing. Due to physiological differences and individual habits, speakers tend to differ in their typical pitch ranges. As a consequence, pitch analysis results are not always easy to interpret and to compare among speakers. In this study, we use the Praat program (Boersma & Weenink 2015) for analyzing pitch in samples of conversational Finnish speech and we use the R statistical programming environment (R Core Team, 2014) for further analysis and visualization. We first describe the general shapes of the speaker-specific pitch distributions and see whether and how the distributions vary between individuals. A bootstrapping method is applied to discover the minimal amount of speech that is necessary in order to reliably determine the pitch mean, median and mode for an individual speaker. The scripts and code written for the Praat program and for the R statistical programming environment are made available under an open license for experimenting with other speech samples. The datasets produced with the Praat script will also be made available for further studies.Peer reviewe

A Short Term Study of Hungarians Learning Finnish Vowels

Turku, FinlandA group of Hungarian students (n=10) participated in a Finnish phonetics and conversation course during the first 3 months of their language studies. During the course, the students trained in the allophonic variation of Finnish speech sounds, comparing them to Hungarian sounds and participating in group conversation exercises. We call the method used on the course conscious phonetic training of foreign language speech sounds. Additionally, the students participated in one-on-one imitating exercises, which were recorded for the current study. We followed the participants' foreign sounds pronunciation development during the first semester of their studies and compared it to their peers (n=4). The results suggest that participating in the course affected the students' pronunciation skills towards the end of the three-month course, whereas, at the beginning, both of the groups' pronunciation was more similar.caslpub3672pu

Pre-speech tongue movements recorded with ultrasound

We analyse Ultrasound Tongue Imaging (UTI) data from five speakers, whose native languages (L1) are English (3 peakers), German (1 speaker), and Finnish (1 speaker). The data consist of single words spoken in the subjects' respective native tongues as responses to a picture naming task. The focus of this study is on automating the analysis of ultrasound recordings of tongue movements that take place after the subject is presented with a stimulus. We analyse these movements with a pixel difference method (McMillan and Corley 2010; Drake, Schaeffler, and Corley 2013a; Drake, Schaeffler, and Corley 2013b), which yields an estimate on the rate of change on a frame by frame basis. We describe typical time dependent pixel difference contours and report grand average contours for each of the speakers.caslpub3534pu

Effect of phonetic onset on acoustic and articulatory speech reaction times studied with tongue ultrasound

We study the effect that phonetic onset has on acoustic and articulatory reaction times. An acoustic study by Rastle et al. (2005) shows that the place and manner of the first consonant in a target affects acoustic RT. An articulatory study by Kawamoto et al. (2008) shows that the same effect is not present in articulatory reaction time of the lips. We hypothesise, therefore, that in a replication with articulatory instrumentation for the tongue, we should find the same acoustic effect, but no effect in the articulatory reaction time. As a proof of concept of articulatory measurement from ultrasound images, we report results from a pilot experiment which also extends the dataset to include onset-less syllables. The hypothesis is essentially confirmed with statistical analysis and we explore and discuss the effect of different vowels and onset types (including null onsets) on articulatory and acoustic RT and speech production.https://www.internationalphoneticassociation.org/icphs/icphs2015caslpub3946pub84

How far are vowel formants from computed vocal tract resonances?

13 pages, 1 figure, 3 tablesWe compare numerically computed resonances of the human vocal tract with formants that have been extracted from speech during vowel pronunciation. The geometry of the vocal tract has been obtained by MRI from a male subject, and the corresponding speech has been recorded simultaneously. The resonances are computed by solving the Helmholtz partial differential equation with the Finite Element Method (FEM). Despite a rudimentary exterior space acoustics model, i.e., the Dirichlet boundary condition at the mouth opening, the computed resonance structure differs from the measured formant structure by $\approx$ 0.7 semitones for [i] and [u] having small mouth opening area, and by $\approx$ 3 semitones for vowels [a] and [ae] that have a larger mouth opening. The contribution of the possibly open velar port has not been taken into considaration at all which adds the discrepancy for [a] in the present data set. We conclude that by improving the exterior space model and properly treating the velar port opening, it is possible to computationally attain four lowest vowel formants with an error less than a semitone. The corresponding wave equation model on MRI-produced vocal tract geometries is expected to have a comparabale accuracy.Non peer reviewe

Visualising speech: Identification of atypical tongue-shape patterns in the speech of children with cleft lip and palate using ultrasound technology

Susan lloyd - ORCID: 0000-0003-4338-3630 https://orcid.org/0000-0003-4338-3630Item deposited in University of Strathclyde (Strathprints) repositpory on 30 April 2018, available at: https://strathprints.strath.ac.uk/id/eprint/63886Previous research by Gibbon (2004) shows that at least 8 distinct error types can be identified in the speech of people with cleft lip and palate (CLP) using electropalatography (EPG), a technique which measures tongue-palate contact. However, EPG is expensive and logistically difficult. In contrast, ultrasound is cheaper and arguably better equipped to image the posterior articulations (such as pharyngeals) which are common in CLP. A key aim of this project is to determine whether the eight error types made visible with EPG in CLP speech described by Gibbon (2004) can be also be identified with ultrasound. This paper will present the first results from a larger study developing a qualitative and quantitative ultrasound speech assessment protocol. Data from the first 20 children aged 3 to 18 with CLP will be presented. Data are spoken materials from the CLEFTNET protocol. We will present a recording format compatible with CAPS-A to record initial observations from the live ultrasound (e.g. double articulations, pharyngeal stops). Two Speech and Language Therapists analysed the data independently to identify error types. Results suggest that all of the error types, for example fronted placement and double articulations can be identified using ultrasound, but this is challenging in real-time. Ongoing work involves quantitative analysis of error types using articulatory measures.http://craniofacialsociety.co.uk

Fetal cardiovascular hemodynamics in type 1 diabetic pregnancies at near-term gestation

Introduction Poor glycemic control in maternal type 1 diabetes mellitus during pregnancy can affect fetal cardiac and placental function. However, studies concerning fetal central hemodynamics have revealed conflicting results. We hypothesized that in pregnancies complicated by maternal type 1 diabetes, fetal cardiovascular and placental hemodynamics are comparable to the control fetuses at near-term gestation. In addition, we investigated the relationship between newborn serum biomarkers of cardiac function and fetal cardiovascular and placental hemodynamics. Furthermore, we studied whether maternal diabetes is associated with placental inflammation. Material and methods In this prospective case-control study, fetal central and peripheral hemodynamics were assessed by ultrasonography in 33 women with type 1 diabetes and in 67 controls with singleton pregnancies between 34(+2)and 40(+2)gestational weeks. Newborn umbilical cord serum was collected to analyze cardiac natriuretic peptides (atrial and B-type natriuretic peptides) and troponin T concentrations. Placental tissue samples were obtained for cytokine analyses. Results Fetal ventricular wall thicknesses were greater and weight-adjusted stroke volumes and cardiac outputs were lower in the type 1 diabetes group than in the control group. Pulsatility in the aortic isthmus and inferior vena cava blood flow velocity waveforms was greater in the type 1 diabetes group fetuses than in the controls. A positive correlation was found between branch pulmonary artery and aortic isthmus pulsatility index values. Umbilical artery pulsatility indices were comparable between the groups. Umbilical cord serum natriuretic peptide and troponin T concentrations were elevated in the type 1 diabetes fetuses. These cardiac biomarkers correlated significantly with cardiovascular hemodynamics. Placental cytokine levels were not different between the groups. Conclusions In maternal type 1 diabetes pregnancies, fetal cardiovascular hemodynamics is impaired. Maternal type 1 diabetes does not seem to alter placental vascular impedance or induce placental inflammation.</p