Articulating: the neural mechanisms of speech production

Speech production is a highly complex sensorimotor task involving tightly coordinated processing across large expanses of the cerebral cortex. Historically, the study of the neural underpinnings of speech suffered from the lack of an animal model. The development of non-invasive structural and functional neuroimaging techniques in the late 20th century has dramatically improved our understanding of the speech network. Techniques for measuring regional cerebral blood flow have illuminated the neural regions involved in various aspects of speech, including feedforward and feedback control mechanisms. In parallel, we have designed, experimentally tested, and refined a neural network model detailing the neural computations performed by specific neuroanatomical regions during speech. Computer simulations of the model account for a wide range of experimental findings, including data on articulatory kinematics and brain activity during normal and perturbed speech. Furthermore, the model is being used to investigate a wide range of communication disorders.R01 DC002852 - NIDCD NIH HHS; R01 DC007683 - NIDCD NIH HHS; R01 DC016270 - NIDCD NIH HHSAccepted manuscrip

The Effects of Humming and Pitch on Craniofacial and Craniocervical Morphology Measured Using MRI

Peer reviewedPreprin

The role of gesture delay in coda /r/ weakening: an articulatory, auditory and acoustic study

The cross-linguistic tendency of coda consonants to weaken, vocalize, or be deleted is shown to have a phonetic basis, resulting from gesture reduction, or variation in gesture timing. This study investigates the effects of the timing of the anterior tongue gesture for coda /r/ on acoustics and perceived strength of rhoticity, making use of two sociolects of Central Scotland (working- and middle-class) where coda /r/ is weakening and strengthening, respectively. Previous articulatory analysis revealed a strong tendency for these sociolects to use different coda /r/ tongue configurations—working- and middle-class speakers tend to use tip/front raised and bunched variants, respectively; however, this finding does not explain working-class /r/ weakening. A correlational analysis in the current study showed a robust relationship between anterior lingual gesture timing, F3, and percept of rhoticity. A linear mixed effects regression analysis showed that both speaker social class and linguistic factors (word structure and the checked/unchecked status of the prerhotic vowel) had significant effects on tongue gesture timing and formant values. This study provides further evidence that gesture delay can be a phonetic mechanism for coda rhotic weakening and apparent loss, but social class emerges as the dominant factor driving lingual gesture timing variation

A single case study of articulatory adaptation during acoustic mimicry

The distribution of fine-grained phonetic variation can be observed in the speech of members of welldefined social groups. It is evident that such variation must somehow be able to propagate through a speech community from speaker to hearer. However, technological barriers have meant that close and direct study of the articulatory links of this speaker-hearer chain has not, to date, been possible. We present the results of a singlecase study using an ultrasound-based method to investigate temporal and configurational lingual adaptation during mimicry. Our study focuses on allophonic variants of postvocalic /r/ found in speech from Central Scotland. Our results show that our informant was able to adjust tongue gesture timing towards that of the stimulus, but did not alter tongue configuration

Analysis of speech and tongue motion in normal and post-glossectomy speaker using cine MRI

Objective Since the tongue is the oral structure responsible for mastication, pronunciation, and swallowing functions, patients who undergo glossectomy can be affected in various aspects of these functions. The vowel /i/ uses the tongue shape, whereas /u/ uses tongue and lip shapes. The purpose of this study is to investigate the morphological changes of the tongue and the adaptation of pronunciation using cine MRI for speech of patients who undergo glossectomy. Material and Methods Twenty-three controls (11 males and 12 females) and 13 patients (eight males and five females) volunteered to participate in the experiment. The patients underwent glossectomy surgery for T1 or T2 lateral lingual tumors. The speech tasks “a souk” and “a geese” were spoken by all subjects providing data for the vowels /u/ and /i/. Cine MRI and speech acoustics were recorded and measured to compare the changes in the tongue with vowel acoustics after surgery. 2D measurements were made of the interlip distance, tongue-palate distance, tongue position (anterior-posterior and superior-inferior), tongue height on the left and right sides, and pharynx size. Vowel formants Fl, F2, and F3 were measured. Results The patients had significantly lower F2/Fl ratios (F=5.911, p=0.018), and lower F3/F1 ratios that approached significance. This was seen primarily in the /u/ data. Patients had flatter tongue shapes than controls with a greater effect seen in /u/ than /i/. Conclusion The patients showed complex adaptation motion in order to preserve the acoustic integrity of the vowels, and the tongue modified cavity size relationships to maintain the value of the formant frequencies

THE LANGUAGE OF MUSIC: LINGUISTICS IN TRUMPET PEDAGOGY

For decades, many brass teachers have relied heavily upon speech as a means of conveying pedagogical concepts. Additionally, a significant number of teachers in the brass community continue to use speech sounds to teach specific kinesthetic responses (i.e. using specific vowels for tone production, particular consonants for articulation, and variations of vowels for different pitch registers). These teaching concepts have been perpetuated over time, though many intricate aspects of human anatomy were yet to be understood at the inception of these methods, including the physiological processes used during speech. As technology has evolved, researchers in the field of linguistics have made significant discoveries regarding the production and perception of speech. As a result of these innovations, researchers now understand more about individual languages than ever before. This document aims to critique popular beliefs regarding speech directives often utilized in trumpet pedagogy, such as guiding a student by saying “tah,” “too,” “tee,” etc. to produce a desired sound concept. A significant portion of this document also outlines an ultrasound experiment conducted by the author in the Phonetics Laboratory at the University of Kentucky, in which exercises were designed to determine if speech vowels are in fact used during trumpet playing. During this study, subjects wore a lightweight headset with an ultrasound probe placed under the chin. The ultrasound probe allowed the researcher a midsaggital (side) view of the subject’s oral cavity, displaying vowel placements and articulatory phenomena. While using the ultrasound imaging technology, subjects played a short selection of musical exercises on B-flat trumpet and then read aloud a pre-selected list of English words, designed to display multiple combinations of vowel and consonant pairings. Both the trumpet exercises and reading of the word list were audio recorded and simultaneously paired with the corresponding ultrasound video data. After playing the selected exercises, subjects completed a brief written questionnaire of personal language history to ascertain possible influences upon dialect. The ultrasound videos were then analyzed with the audio recordings to map each individual’s tongue placements during speech as compared to the placements utilized during trumpet playing. The author concluded that a majority of participants did not use the specific placements of speech vowels while playing the trumpet, although some participant data displayed a slightly stronger correlation than others. While many conclusions could be drawn from this research study, the corresponding data is intended for a purely observational understanding of the influence of linguistics upon trumpet performance and pedagogy. This document is presented in two parts: Part I contains introductory research material, as well as the process, analysis, and conclusions from the experiment outlined above. Part II contains recital programs and corresponding program notes in fulfillment of the degree of Doctor of Musical Arts in Trumpet Performance, as well as a personal vita