In 1886, a group of French and British language teachers, led by the French linguist Paul Passy, formed what would come to be known from 1897 onwards as the International Phonetic Association (in French, l’Association phonétique internationale). Their original alphabet was based on a spelling reform for English known as the Romic alphabet, but in order to make it usable for other languages, the values of the symbols were allowed to vary from language to language. For example, the sound [ʃ] (the sh in shoe) was originally represented with the letter ⟨c⟩ in English, but with the digraph ⟨ch⟩ in French. However, in 1888, the alphabet was revised so as to be uniform across languages, thus providing the base for all future revisions. The idea of making the IPA was first suggested by Otto Jespersen in a letter to Paul Passy. It was developed by Alexander John Ellis, Henry Sweet, Daniel Jones, and Passy.
Since its creation, the IPA has undergone a number of revisions. After revisions and expansions from the 1890s to the 1940s, the IPA remained primarily unchanged until the Kiel Convention in 1989. A minor revision took place in 1993 with the addition of four letters for mid central vowels and the removal of letters for voiceless implosives. The alphabet was last revised in May 2005 with the addition of a letter for a labiodental flap. Apart from the addition and removal of symbols, changes to the IPA have consisted largely of renaming symbols and categories and in modifying typefaces.
Extensions to the International Phonetic Alphabet for speech pathology were created in 1990 and officially adopted by the International Clinical Phonetics and Linguistics Association in 1994.