Comparative work of the Afroasiatic languages uses a semi-conventionalized set of symbols that are somewhat different than the International Phonetic Alphabet and other phonetic notations. The more salient differences include the letters ⟨c, ʒ⟩ for IPA [ts, dz], the circumflex diacritic ⟨◌̂⟩ for lateral obstruents, and the sub-dot ⟨◌̣⟩ for emphatic consonants, which depending on the language may be ejective, implosive or pharyngealized.