Lengua o hablante? -Investigando las alternancias coronal-velares en Vilela

Fieldwork elicitation on Vilela, an endangered language of the Chaco area, revealed an alternation between /t/ and /k/. We documented t/k-alternation in a set of suffixes, but even cases at initial position and within a single sequence of the same item have been found. For the analysis we separate the alternations out into those connected to a general tendency of assibilation involving coronalization and palatalization and those that are fluctuations between stops. An investigation of the nature of context, frequency and order of occurrence of the alternation confirms preferred contexts of high vowels and a presumably typical velar-coronal order. Acoustic-phonetical salience of this alternation is demonstrated on collected field data by means of durational and spectral measures. Whereas the stop fluctuations can be ascribed to some specificities of the last speaker, such alternations assigned to assibilation and palatalization (fronting) reflect the sound change processes of the area.