ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06
4aSC26. The gestural and temporal organization of assimilation.
Sidney A. J. Wood
Dept. of Linguistics, Helgonabacken 12, 22362 Lund, Sweden
Ever since Wang and Fillmore [J. Speech Hear. Res. 4, 130 (1961)]
phoneticians have distinguished between nonpredictable language-specific speech
habits and predictable universal articulatory constraints, the former being
cortical and extrinsic to the vocal tract, the latter intrinsic to the vocal
tract and the consequence of articulation mechanics. Assimilation came to be
seen as an intrinsic vocal tract process, explained in terms of Ohman's model
of coarticulation [ 151 (1966)]. This contrasts with classical
phonetics where assimilation is the result of preplanned reorganization of
articulation. The work reported in this paper favors the classical view.
Gestures involved in an assimilation are initiated earlier, delayed, or are
held longer, than in nonassimilated situations. It is argued that this revision
of gesture timing in relation to adjacent activity is an expression of
preplanning of motor commands that takes place in the cortex where there is
access to larger portions of the utterance (the subcortical motor structures
have limited access and cannot advance or delay gestures). Examples of
palatalization of Bulgarian apico-alveolar stops and Swedish palatovelar stops
are presented. The data are analyzed from x-ray motion films by procedures
described by Wood [J. Phon. 19, 281 (1991)].