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StopNCo - Effort and coordination in the production of stop consonants

Project Coordinator : Maëva GARNIER

Project realized thanks to the support of : ANR Jeune Chercheur

Start date : 2015/03/01

Duration : 48 mounths

We often admire high-level athletes for their extraordinary performances and for the precise coordination of their gestures. We forget that we are all vocal athletes too! Speech, that we produce everyday in an automatic way, actually requires a very precise coordination of breathing, laryngeal and articulatory gestures, which takes some time for children to master, and which can dysfunction in the case of voice or speech disorders. The production of stop consonants (/p/, /b/, ...) is of particular interest for a better understanding of speech control, as it requires a coordination of speech gestures not only in their amplitude and force, but also in their timing. Children with articulation disorders very often have troubles with this category of sounds, while dysphonic patients demonstrate excessive tensions and efforts. 
The project StopNCo aims at improving our understanding of speech control by addressing 4 questions: 

1. Which acoustic features are crucial for the intelligibility of stop consonants? 
Instead of the traditional laboratory approach that examines the perceptual consequence of varying features in synthetic stimuli, we will here characterize how speakers enhance their speech in interactive situations requiring intelligibility, but where acoustic cues are altered or missing (speech produced in a noisy or reverberant environment, whispered speech, …). 

2. Which coordination of breathing, laryngeal and articulatory gestures enables the variation of these acoustic features, with what extent of physical constraints vs. speaker-specific control?  
We will collect simultaneously acoustic, aerodynamic (intra-oral pressure, airflow), laryngeal (electroglottography, endoscopy) and articulatory data (movement, force sensors, surface EMG). We will explore how the coordination of breathing, laryngeal and articulatory gestures varies with the speaking mode (murmured to shouted, whispered, fast, clear speech) and using speech perturbation paradigms (filtered auditory feedback, perturbed articulation, oral anesthetic, …).  

3. How does this control develop normally in children and dysfunction in some of them?  
We will characterize how the acoustic cues to stop consonants are refined with child age, or remain deviant in children with functional articulation disorders. Using non invasive methodologies, we will identify some aspects of speech coordination that differ from adult speech, and that some children with articulation disorders have troubles to develop. 

4. How the coordination of speech gestures can vary in efficiency?  
This will first require the development of methodologies to measure or estimate laryngeal and articulatory efforts. Production efforts will be compared between non pathological adult speakers and dysphonic patients, hypothesized to coordinate less efficiently their breathing, laryngeal and articulatory gestures. 

A functional functional model of speech coordination in the production of stop consonants will be built, taking into account the different physiological levels and perceptual outcomes, the intra and inter-speaker. 

The financial help requested mainly aims at recruiting a Ph.D student and a one-year post-doctoral researcher, so as to help me build a team around the questions of speech production efforts and stop consonants production that are not very developed in the GIPSA-lab yet. The consortium will be composed of a limited number of people, mainly from GIPSA-lab but also from the university of Lyon 1 and from the medical field, most of them beeing young researchers. Each collaborator will bring a specific expertise – in speech physiology and pathology, in biomechanics and in speech development in children – complementary to mine in vocal effort, speech adaptation and face to face interaction. 

The project will bring fundamental knowledge on speech efforts and coordination, as well as new measurement methodologies and indices for the diagnosis and the rehabilitation of speech disorders.

GIPSA-lab, 11 rue des Mathématiques, Grenoble Campus BP46, F-38402 SAINT MARTIN D'HERES CEDEX - 33 (0)4 76 82 71 31