Depends on the language. In some languages it's /ɛ/ (English "eh"), in others it's /e/ (Scottish English "ay"), and in yet others it's /e̞/ (halfway between th

Depends on the language. In some languages it's /ɛ/ (English "eh"), in others it's /e/ (Scottish English "ay"), and in yet others it's /e̞/ (halfway between the two). It's rarely /ɛɪ/ ("ay" in most dialects of English), though it appears in many other languages written as something other than "e". Dutch is an interesting case: /ɛ/, /e/, and /ɛɪ/ are all different phonemes (short "e", long "e"/"ee", and "ei"/"ij" respectively). Many only have one. Greek just has /ɛ/. Japanese just has /e̞/.