Are there differences between [ə] and [ɯ] formants in Mapudungun spoken by bilingual children from Alto Bío-Bío?

Abstract

The first studies about the Mapudungun sixth vowel, performed from an articulatory perspective, have associated it with two allophones: one central [ə] and another posterior [ɯ]. However, acoustic studies do not report a posterior allophone [ɯ], but a central one. This work presents an acoustic description of the Mapudungun sixth vowel produced by bilingual children from Alto Bío-Bío. An analysis of the normalized first two formants of /ə/ realizations was performed and a series of comparisons of these results between communities and sectors was made. The results show the presence of two allophones: one posterior-central in contexts where [ə] should be produced, and a central one in contexts where [ɯ] should be produced. These results are consistent with previous studies performed from an acoustic perspective but differ from the first articulatory approaches.