The five established major language families are: A number of language groups in Arunachal Pradesh traditionally considered to be Sino-Tibetan (Tibeto-Burman) may in fact constitute independent language families or isolates (Roger Blench 2011).Several macrofamily schemes have been proposed for linking multiple language families of Southeast Asia.None of these proposals have been accepted by mainstream comparative linguistics, though research into higher-level relationships among these languages has gained some renewed scholarly interest over the last three decades; the various hypotheses are still under investigation, and the validity of each has yet to be resolved.[2] Genetic similarities between the peoples of East and Southeast Asia have led some scholars such as George van Driem to speculate about "Haplogroup O languages".The following table compares the phonemic inventories of various recently reconstructed proto-languages of Southeast Asia.