Evidence for the interdental/alveolar contrast in the Mapudungun spoken on the coast: an acoustic and statistical study

Mauricio A. Figueroa Candia – Universidad de Concepción, Chile
Gastón F. Salamanca Gutiérrez – Universidad de Concepción, Chile
Juan H. Painequeo Paillán – Universidad de la Frontera, Chile
David A. Bertín González – Universidad de la Frontera, Chile
Camila Márquez Pradenas – Universidad de Concepción, Chile

Mauricio A. Figueroa Candia, Gastón F. Salamanca Gutiérrez, Juan H. Painequeo Paillán, David A. Bertín González y Camila Márquez Pradenas, 2019: "Evidencia del contraste interdental/alveolar en el mapudungun hablado en la costa: un estudio acústico-estadístico", Onomázein 44, 191-216.
DOI: 10.7764/onomazein.44.09

Most previous research on Mapudungun has argued for the existence of a phonemic contrast between interdental—[l], [n], and [t]—and alveolar segments—[l], [n], and [t]2 (e.g., Echeverría, 1964; Salas, 1976). However, some studies have challenged this hypothesis (e.g., Croese, 1980; Smeets, 1989; Salamanca & Quintrileo, 2009), particularly when analysing data from Mapudungun spoken in areas with a strong Spanish presence. This study aims to provide evidence to determine whether this contrast is present in the speech of 19 participants from Toltén and Mariquina. In order to do this, locus equations were used (Sussman, McCaffrey, & Matthews, 1991; Sussman, Hoemeke, & Ahmed, 1993), as well as several types of regression analyses. These techniques aimed to ascertain whether statistically significant differences exist between the acoustic correlates of place of articulation obtained from interdental and alveolar segments, in three manners of articulation: lateral, nasal and voiceless plosive. The effects on the acoustic data of the variables vowel and sex was also explored. The results of analysing 3437 tokens suggested that there is evidence to support the hypothesis of a phonemic contrast for lateral and plosive consonants, but not for nasals; also, there was a statistically significant effect of vowel and sex. In sum, these results suggest that the phonemic contrast between interdental and alveolar nasals is weakening, which has important implications for Mapudungun dialectology. From a methodological perspective, this study highlights the importance of including techniques from acoustic phonetics and inferential statistics in the study of Chilean vernacular languages.