Phonetic Characterization of Stop Manner Contrasts in Four Australian Languages

A minority of Australian languages contrast stops at the same place of articulation – oppositions described in a variety of ways: e.g. fortis vs lenis, geminate vs singleton – but not well understood due to a lack of instrumental data. To shed more light on these contrasts, acoustic phonetic properties of stops were analyzed in medial pre-vocalic environments in Kamu, Larrakia, Warlmanpa, and Warumungu. In all four languages, stops at the same place of articulation are differentiated primarily by duration, and also degree of voicing estimated using Harmonic Ratios. There is a degree of correlation between voicing and duration, but duration is found to be the property that most consistently differentiates stop modes. These data suggest that the opposition in these languages is best characterised as a length contrast, and that these stop oppositions are realized with complex interactions between duration and voicing.