Gestural organization in Spanish: An experimental study of spirantization and aspiration

This study investigates the articulatory mechanisms that underlie the distinction between two types of continuant segments in the Andalusian dialect of Spanish. These two types of continuants--voiced approximants and fricatives--arise from the effects of two common phonological processes of the language: spirantization and s-aspiration. Voiced approximants are the result of spirantization of underlying voiced stops /b, d, g/. Voiced fricatives result from the interaction of spirantization and s-aspiration in the underlying contexts /sb, sd, sg/. The resulting surface contrast provides an opportunity to investigate the phonetic realization of manner of articulation distinctions.^ Existing accounts of the articulatory mechanisms that control manner of articulation distinctions mention the degree and area of the constriction as the primary parameter. In this view, it is possible to imagine a constriction degree continuum that would have, at one end, a complete closure or stop and, at the other end, a fully open vowel. Between those two end points, fricatives are distinguished from approximants by virtue of having a smaller constriction degree. In contrast, the hypothesis introduced in this study suggests that there is no such difference in constriction degree between fricatives and approximants. Instead, the two differ primarily in terms of duration: fricatives are significantly longer than approximants.^ In order to test that hypothesis, a series of experiments were performed in which the articulatory characteristics of labial, dental and velar approximants and fricatives were investigated. The experiments were carried out with the use of an electromagnetic midsagittal articulometer. Data were collected from four native speakers of Andalusian Spanish. The obtained signals were processed in order to obtain estimates of constriction degree and duration of the representative articulatory movements.^ Results of a statistical analysis performed of the data suggest that, indeed, fricatives and approximants do not differ in terms of constriction degree. The results for duration, however, confirm the proposed hypothesis: fricatives are significantly longer than approximants. With a few exceptions, the same pattern is observed for all three points of articulation.