Biblical Hebrew had a typical Semitic consonant inventory, with pharyngeal /ʕ ħ/, a series of "emphatic" consonants (possibly ejective, but this is debated), lateral fricative /ɬ/, and in its older stages also uvular /χ ʁ/. /χ ʁ/ merged into /ħ ʕ/ in later Biblical Hebrew, and /b ɡ d k p t/ underwent allophonic spirantization to ɣ ð x f θ (known as begadkefat). The earliest Biblical Hebrew vowel system contained the Proto-Semitic vowels /a aː i iː u uː/ as well as /oː/, but this system changed dramatically over time.