is pronounced [o] after labial consonants, an allophonic effect salient enough to be encoded in pinyin transliteration: velar /xɤ/ he vs. labial /pɤ/ bo. In Vietnamese , the opposite assimilation takes place: velar codas /k/ and /ŋ/ are pronounced as labialized [kʷ] and [ŋʷ] , or even labial-velar /kp/ and /ŋm/