 The Proto-Semitic glottal stop , as well as the fricatives , , are lost as consonants, either by sound change or orthographically, but they gave rise to the vowel quality "e" not exhibited in Proto-Semitic.The voiceless lateral fricatives () merged with the sibilants as in Canaanite, leaving 19 consonantal phonemes.Old Akkadian preserved the /*ś/ phoneme longest but it eventually merged with /*š/, beginning in the Old Babylonian period.