Phonological contrast and phonetic variation: The case of velars in Iwaidja: Supplementary material

A field-based ultrasound and acoustic study of Iwaidja, an endangered Australian aboriginal language, investigated the phonetic identity of non-nasal velar consonants in intervocalic position, where past work had proposed a [+continuant] vs [-continuant] phonemic contrast. We analyzed the putative contrast within a continuous phonetic space, defined by both acoustic and articulatory parameters, and found gradient variation from more consonantal realizations, e.g. [ɰ], to more vocalic realizations, e.g. [a]. The distribution of realizations across lexical items and speakers did not support the proposed phonemic contrast. This case illustrates how lenition that is both phonetically gradient and variable across speakers and words can give the illusion of a contextually restricted phonemic contrast.*