Articulatory Phonology 1 What is a speech gesture 2 How are gestures coordinated with each other 3 How does this help explain phonological patterns Note this lecture is an overview of work done primarily by Catherine Browman and Louis Goldstein Haskins Labs Yale University What is a speech gesture 1 Coordinative structure articulators and the muscles that move them are organized to produce vocal tract constrictions 2 Dynamic system using a spring mass model to simulate the internal dynamics of articulator motion note the system we are discussing here is an implemented model of phonology i e it is tied to a speech synthesizer and produces speech It is a research system which is not complete It is intended to point the way toward a complete model by outlining an approach that in principle can be expanded upon as more knowledge about the articulators is acquired and better speech synthesis methods are developed Coordinative structures Lip constriction two gestural specifications LP lip protrusion LA lip aperture Tongue tip constriction TTCL tongue tip constriction location TTCD tongue tip constriction degree Tongue body constriction TBCL tongue body constriction location TBCD tongue body constriction degree Velo pharyngeal port constriction VEL velic aperture Glottal constriction GLO glottal aperture Dynamics The motions of the articulators are calculated as a damped mass spring model mx bx k x u 0 m mass set to 0 in this implementation b damping set to critical damping so there is no oscillation k the spring stiffness x the current location of the mass x velocity x acceleration u the new target location of the mass b m x u k 2 How are gestures coordinated with each other A gestural score coordinates the gestures Relative timing specified in terms of phase relations among gestures activation interval specification of u and k for TDCL narrow and TBCD phar The gestural score with its specifications of dynamic system parameters then produces smooth time varying movement curves of the articulators 3 How does this help explain phonological patterns The gestural approach to phonology is good at offers important insight into assimilation deletion resyllabification metathesis maybe But not good at morphophonemics dissimilation perceptually driven sound change perfect memory spoken with an aspirated t Gestural hiding can cause deletion perfect memory spoken with a deleted t but the tongue blade gesture is still there Another case of deletion via gestural hiding nabbed most pronounced as n bmo st but the alveolar closure gesture is still there seven plus seven with an alveolar n between v and b dip in lower lip vertical location Gestural hiding can cause assimilation seven plus seven with an assimilated m but the tongue blade gesture is still there Gestural blending can result in assimilation Movement of the tongue tip in l t and ld in Castilian Spanish Place of articulation is backer for l than for t and presumably also d Place of articulation in the ld sequence is a blend of the two Romero Joaqu n 1996 Articulatory blending of lingual gestures Journal of Phonetics 24 99 111 Gestural reorganization can lead to resyllabification kiss ted spoken more and more quickly at the fastest rate the t becomes t as if the syllable break moved k s t d k st d Phase of single glottal opening gesture in st is timed as for the cluster losing the normal phasing for t s Glottal aperture t s t s t st Assimilation is different from gestural blending Consider the s sequence in tops shop Is it or a gesturally blended s Notice that the s sequence in fish soup behaves a little differently with less apparent assimilation of to s Francis Nolan Tara Holst and Barbara K hnert 1996 Modelling s to accommodation in English J Phon 24 113 137 Some references Browman C P Goldstein L 1986 Towards an articulatory phonology Phonology Yearbook 3 219 252 Browman C P Goldstein L 1989 Articulatory gestures as phonological units Phonology 6 201 251 Browman C P Goldstein L 1990a Gestural specification using dynamically defined articulatory structures Journal of Phonetics 18 299 320