PRESLA: An original device to measure the mechanical interaction between tongue and teeth or palate during speech production

An original experimental procedure is presented to measure the mechanical interaction between tongue and teeth and palate during speech production. It consists in using edentulous people as subjects and to insert pressure sensors in the structure of a replication of their dental prosthesis. This is assumed to induce no speech production perturbation for subjects who are used to speak with their prosthesis. Data collected from 4 subjects of French demonstrate the usability of the system

Motor Equivalence in Speech Production

International audienceThe first section provides a description of the concepts of “motor equivalence” and “degrees of freedom”. It is illustrated with a few examples of motor tasks in general and of speech production tasks in particular. In the second section, the methodology used to investigate experimentally motor equivalence phenomena in speech production is presented. It is mainly based on paradigms that perturb the perception-action loop during on-going speech, either by limiting the degrees of freedom of the speech motor system, or by changing the physical conditions of speech production or by modifying the feedback information. Examples are provided for each of these approaches. Implications of these studies for a better understanding of speech production and its interactions with speech perception are presented in the last section. Implications are mainly related to characterization of the mechanisms underlying interarticulatory coordination and to the analysis of the speech production goals

Speech outcomes after glossectomy for tongue cancer a critical review of the literature

"A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, December 31, 2004."Also available in print.Thesis (B.Sc)--University of Hong Kong, 2004.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

Real-time decoding of question-and-answer speech dialogue using human cortical activity.

Natural communication often occurs in dialogue, differentially engaging auditory and sensorimotor brain regions during listening and speaking. However, previous attempts to decode speech directly from the human brain typically consider listening or speaking tasks in isolation. Here, human participants listened to questions and responded aloud with answers while we used high-density electrocorticography (ECoG) recordings to detect when they heard or said an utterance and to then decode the utterance's identity. Because certain answers were only plausible responses to certain questions, we could dynamically update the prior probabilities of each answer using the decoded question likelihoods as context. We decode produced and perceived utterances with accuracy rates as high as 61% and 76%, respectively (chance is 7% and 20%). Contextual integration of decoded question likelihoods significantly improves answer decoding. These results demonstrate real-time decoding of speech in an interactive, conversational setting, which has important implications for patients who are unable to communicate

What role does the palate play in speech motor control? Insights from tongue kinematics for German alveolar obstruents

By means of simultaneous EMMA and EPG recordings, we investigated tongue tip kinematics and tongue palate contact patterns for four German speakers in order to compare production strategies of alveolar stops with fricatives. For alveolar stops versus fricatives, two different control strategies were hypothesized: a target above the contact location for alveolar stops resulting in a collision of the tongue tip at the palate as opposed to a precise positioning of the tongue at the lateral margins at the palate for alveolar fricatives. Additionally, we suspected differences between stops and fricatives with respect to anterior and lateral palate contacts and their influence on tongue kinematics. Results of this study confirmed two different control strategies for alveolar stops and fricatives by means of significant differences in movement amplitude, velocity, and duration of the closing gesture, the amplitude of deceleration peaks, tongue tip movement during acoustically defined closure and constriction, and maximal anterior contact during closure. Additionally, results for speaker dependent mechanisms were related to the subject's coronal palatal shape

Perceptual Calibration of F0 Production: Evidence from Feedback Perturbation

Hearing one’s own speech is important for language learning and maintenance of accurate articulation. For example, people with postlinguistically acquired deafness often show a gradual deterioration of many aspects of speech production. In this manuscript, data are presented that address the role played by acoustic feedback in the control of voice fundamental frequency (F0). Eighteen subjects produced vowels under a control ~normal F0 feedback! and two experimental conditions: F0 shifted up and F0 shifted down. In each experimental condition subjects produced vowels during a training period in which their F0 was slowly shifted without their awareness. Following this exposure to transformed F0, their acoustic feedback was returned to normal. Two effects were observed. Subjects compensated for the change in F0 and showed negative aftereffects. When F0 feedback was returned to normal, the subjects modified their produced F0 in the opposite direction to the shift. The results suggest that fundamental frequency is controlled using auditory feedback and with reference to an internal pitch representation. This is consistent with current work on internal models of speech motor control

: How compensation mechanisms can inform us about phonemic targets

International audienceThe present study describes the results of a 2 week perturbation experiment where speakers' vocal tract shape was modified due to the presence of an artificial palate. The aim of the work is to investigate whether speakers adapt towards acoustic or articulatory targets. Speakers were recorded regularly over the adaptation time via electromagnetic articulography and acoustics. Immediately after perturbation onset speakers' auditory feedback was masked with white noise in order to investigate speakers' compensatory behaviour when auditory feedback was absent. The results of acoustic measurements show that in vowel production speakers compensate very soon. The compensation in fricatives takes longer and is in some cases not completed within the two weeks. Within a session and for each speaker the sounds can be distinguished solely by acoustic parameters. The difference between the session when no auditory feedback was available and the session when auditory feedback was available was greater for vowels with less palatal contact than for vowels with much palatal contact. In consonant production auditory feedback is primarily used in order to adapt sibilant productions. In general, adaptation tries to keep or enlarge the articulatory and acoustic space between the sounds. Over sessions speakers show motor equivalent strategies (lip protrusion vs. tongue back raising) in the production of /u/. Measurements of tangential jerk suggest that after perturbation onset there is an increase in articulatory effort which is followed by a decrease towards the end of the adaptation time. The compensatory abilities of speakers when no auditory feedback is available suggest that speakers dispose of an articulatory representation. The fact that motor equivalent strategies are used by the speakers, however, supports acoustic representations of speech. It is therefore concluded that articulatory representations belong to the speech production tasks. However, since they are modified as soon as the acoustic output is not the desired one any more, they rather function in the domain of movement organisation and the acoustic representations dominate