As early Austroasiatic speakers dispersed rapidly via waterways, they would have encountered speakers of older language families who were already settled in the area, such as Sino-Tibetan.
æz ˈɜːli ˌɔːstɹoʊsɪˈæɾɪk spˈiːkɚz dɪspˈɜːst ɹˈæpɪdli vˈaɪə wˈɔːɾɚwˌeɪz, ðeɪ wʊdhɐv ɛŋkˈaʊntɚd spˈiːkɚz ʌv ˈoʊldɚ lˈæŋɡwɪdʒ fˈæmɪliz hˌuː wɜːɹ ɔːlɹˌɛdi sˈɛɾəld ɪnðɪ ˈɛɹiə, sˈʌtʃ ɐz sˈiːnoʊɾɪbˈɛtən.