Dynamics of consonant reduction

2014-08-08Many speech sounds undergo weakening, or lenition. Flapping of English /t/ intervocalically is one well‐documented example (e.g. wri[t]e vs. wri[ɾ]er), as is the shift of the series /t:, t, d/ to /t, d, Ø/ from Latin to many Romance varieties. Many phonological analyses of lenition have been proposed, ranging from feature spreading to a modulation of the intended gestural constriction degree at the planning level. Most of these analyses, however, fail to account for the wide variability in realization of segments which can undergo lenition; this variation is often relegated to a separate phonetic level or ignored entirely. This dissertation suggests an alternative proposal, based in Articulatory Phonology, which posits that many cases of lenition can be attributed to an intrinsic link between duration and magnitude of speech gestures. Specifically, I hypothesize that lenition results from undershoot of articulatory targets caused by reduced gestural duration, particularly in prosodically weak positions. ❧ This dissertation consists of three studies. The first two explicitly test the hypothesis that lenition is driven by prosodically‐conditioned temporal reduction. The first chapter examines spirantization in Spanish voiced stops via electromagnetic articulometry and articulatory modeling. The second study tests reduction in coronal oral and nasal stops (/t/, /d/, and /n/) in American English and Spanish using real‐time magnetic resonance imaging. Results from both studies support the hypothesis that spatial reduction is linked to prosodically‐conditioned temporal variation. The third study proposes a model of how this prosodically‐conditioned variability could lead to diachronic sound change over time