Ayin (also ayn or ain; transliterated ) is the sixteenth letter of the Semitic scripts, including Phoenician , Hebrew , Aramaic , Syriac ܥ, and Arabic (where it is sixteenth in abjadi order only). The letter represents a voiced pharyngeal fricative () or a similarly articulated consonant. In some Semitic languages and dialects, the phonetic value of the letter has changed, or the phoneme has been lost altogether (thus, in the revived Modern Hebrew it is reduced to a glottal stop or is omitted entirely in part due to European influence). The Phoenician letter is the origin of the Greek, Latin and Cyrillic letter O, O and O. It is the origin of letter Ƹ. Origins The letter name is derived from Proto-Semitic "eye", and the Phoenician letter had the shape of a circle or oval, clearly representing an eye, perhaps ultimately (via Proto-Sinaitic) derived from the ı͗r hieroglyph (Gardiner D4). The Phoenician letter gave rise to the Greek Ο, Latin O, and Cyrillic О, all representing vowels. The sound represented by ayin is common to much of the Afroasiatic language family, such as in the Egyptian language, the Cushitic languages and the Semitic languages. Transliteration In Semitic philology, there is a long-standing tradition of rendering Semitic ayin with the Greek rough breathing mark (e.g. Arabs). Depending on typography, this could look similar to either an articulate single opening quotation mark (e.g. ). or as a raised semi-circle open to the right (e.g. ). This is by analogy to the transliteration of alef (glottal stop, hamza) by the Greek smooth breathing mark , rendered as single closing quotation mark or as raised semi-circle open to the left. This convention has been adopted by DIN in 1982 and by ISO in 1984 for Arabic (DIN 31635, ISO 233) and Hebrew (DIN 31636, ISO 259). The shape of the "raised semi-circle" for ayin and alef was adopted by the Encyclopedia of Islam (edited 1913–1938, 1954–2005, and from 2007), and from there by the International Journal of Middle East Studies. This convention has since also been followed by ISO (ISO 233-2 and ISO 259-2, 1993/4) and by DIN. A notable exception remains, ALA-LC (1991), the system used by the Library of Congress, continues to recommend modifier letter turned comma (for Hebrew) or left single quotation mark (for Arabic). The symbols for the corresponding phonemes in the International Phonetic Alphabet, for pharyngeal fricative (ayin)