Sir Baldwin Spencer documented the didgeridoo’s crucial function in the ceremonies of the Northern Territory. Spencer also listed the sacred names “jiboulu” for the everyday trumpet and its ritual counterpart, “Purakakka.”
Spencer, in his analysis of recordings, referred to the work of Roth, who documented the term “yiki-yiki” for a long wooden trumpet used in areas of Cape York Peninsula.
From Central Australia, Spencer and Gillen described the “ilpirra” (or “ulpirra”), a shorter, rudimentary tube used in love-magic ceremonies, which they distinguished as a “rudimentary trumpet” that was sung through to intensify the voice rather than played with vibrating lips.
The evidence suggests that while the instrument was widespread in Arnhem Land, its presence elsewhere was more sporadic. The theory proposed in that analysis is that the instrument, or the idea of it, likely “entered the continent here from the north, possibly as a wooden imitation of the shell trumpet.” Once adopted, it was “highly favoured in song and dance ceremonies” and consequently “spread east through the Gulf country (Roth), west to the Kimberleys and south as far as the MacDonnell ranges” (Museums Victoria article).
Hence, the didgeridoo was primarily used in northern Australia, with its traditional heartland being Arnhem Land in the Northern Territory. Its use was more sporadic elsewhere on the continent.