"Yodels can be heard only in the Alps"
The chorus of German folk songs appears sometimes interventions of Japanese singing chirruping sounds for public amusement. But this kind of singing was already known by African pygmies and Inuit, but also in ancient China, Southeast Asia, the Caucasus and Romania, before becoming popular in Austria and the Bavarian Alps of at late eighteenth century. The sounds are produced by rapid alternation between a chest voice and the throat. It is heard well remotely so that shepherds or hunters can contact each others at great distances.