https://www.youtube.com/watch?v=nxX2YQIcRZk

https://www.youtube.com/watch?v=nXKBx67GzVo

From Wikipedia:

Katajjaq

Katajjaq (also pirkusirtuk and nipaquhiit) is a type of traditional competitive song, considered a game, usually held between two women. It is one of the world's few examples of overtone singing, a unique method of producing sounds that is otherwise best known in Tuvan throat-singing. When competing, two women stand face-to-face and sing using a complex method of following each other, thus that one voice hits a strong accent while the other hits a weak, melding the two voices into a nearly indistinguishable single sound. They repeat brief motifs at staggered intervals, often imitating natural sounds, like those of geese, caribou or other wildlife, until one runs out of breath, trips over her own tongue, or begins laughing, and the contest is then over. "The old woman who teaches the children corrects sloppy intonation of contours, poorly meshed phrase displacements, and vague rhythms exactly like a Western vocal coach."[9]
Vocal games

Inuit vocal games are usually played by two women facing each other in close proximity. They use the other participant's oral cavity as resonators but may also play under a kitchen pot for the resonances to be more pronounced. The game consists of repeating meaningless words in tight rhythmic canon. The strong accent of one participant coincides with the weak of the other. The breathing of the players are thus also alternated. Vocal techniques include voiced and voiceless articulations and different articulations, and different placement of sound in the chest, throat and nose areas.

Vocal games are unique to the Inuit.