Electronic instruments to measure tongue and lip pressures and pressure patterns in Australian aborigines made it possible to differentiate physiologically between certain sounds. Lingual pressure patterns indicate that the /t/, /nt/ and /tj/ sounds in the Walbiri language require different articulatory gestures and are properly considered separate phonemes. Labial pressures distinguish classes of phonemes but not individual sounds. Tongue positioning within the oral cavity of aborigines reveals compensations for their different anatomy, but articulatory gestures are remarkably similar in aborigines and Americans.