Sino-Tibetan influence is extensive in Austroasiatic.
During the Middle Neolithic, hunter-gatherers from the Sichuan/Yunnan region who had recently transitioned to agriculture migrated down into the Upper Pearl River region, where they interacted and mixed with the indigenous pre-Austroasiatic ("Old Lingnan") hunter-gatherers. The pre-Austroasiatic foragers adopted the sesquisyllabic syllable structure of these early Sino-Tibetan speakers, as well as various basic words such as: head louse, rain, leaf, sun/day, eat, die/kill, etc.