I thought it was a traditional Indigenous Australian piece but the story is a little more interesting. The basic song has been adapted and arranged for choral work. Tunggare is the first movement of 'Man to Tree', a work commissioned by the Australian Society for Music and was composed by Steven Leek in 1997. We are singing it in four parts with some hand clapping, a capella. (Not sure of the spelling.) The title simply means sing, or a joyful voice. It is really hard to learn because the words do not give you any clues about when to change notes or add expression. It is the same word repeated throughout the entire song, maybe 200 times.
The sound seems like northern South Australia, maybe Central Desert. It seems like a women's song, but I am not sure. It is definitely not a sacred piece.
There are several clips on Youtube, but I liked this the best. The choir is German and it appears that they are singing songs from several different cultures in a concert. I thought the pronunciation was more accurate and less Anglicised than in the other clips.