International Phonetic Alphabet

The International Phonetic Alphabet (IPA) is an alphabetic system of phonetic notation based primarily on the Latin script. It was devised by the International Phonetic Association in the late 19th century as a standard written representation for the sounds of speech. The IPA is used by linguists, lexicographers, foreign language students and teachers, speech–language pathologists, singers, actors, constructed language creators, and translators.

The IPA is designed to represent those qualities of speech that are part of lexical (and, to a limited extent, prosodic) sounds in spoken (oral) language: phones, intonation and the separation of syllables. To represent additional qualities of speech – such as tooth gnashing, lisping, and sounds made with a cleft palate – an extended set of symbols may be used.

Segments are transcribed by one or more IPA symbols of two basic types: letters and diacritics. For example, the sound of the English letter ⟨t⟩ may be transcribed in IPA with a single letter: [t], or with a letter plus diacritics: [t̺ʰ], depending on how precise one wishes to be. Similarly, the French letter ⟨t⟩ may be transcribed as either [t] or [t̻]: [t̺ʰ] and [t̻] are two different, though similar, sounds. Slashes are used to signal phonemic transcription; therefore, /t/ is more abstract than either [t̺ʰ] or [t̻] and might refer to either, depending on the context and language.

Occasionally, letters or diacritics are added, removed, or modified by the International Phonetic Association. As of the most recent change in 2005, there are 107 segmental letters, an indefinitely large number of suprasegmental letters, 44 diacritics (not counting composites), and four extra-lexical prosodic marks in the IPA. These are illustrated in the current IPA chart, posted below in this article and on the International Phonetic Association's website.

In 1886, a group of French and English language teachers, led by the French linguist Paul Passy, formed what would be known from 1897 onwards as the International Phonetic Association (in French, l'Association phonétique internationale). The idea of the alphabet had been suggested to Passy by Otto Jespersen. It was developed by Passy along with other members of the association, principally Daniel Jones. The original IPA alphabet was based on the Romic alphabet, an English spelling reform created by Henry Sweet that, in turn, was based on the Palaeotype alphabet of Alexander John Ellis, itself derived from Lepsius Standard Alphabet first used for transcribing Ancient Egyptian into German.

The original intent was 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⟩ for English but with ⟨x⟩ for French and German; with German, ⟨c⟩ was used for the [x] sound of Bach. With a growing number of transcribed languages this proved impractical, and in 1888 the values of the letters were made uniform across languages. This would provide the base for all future revisions.

Since its creation, the IPA has undergone a number of revisions. After relatively frequent revisions and expansions from the 1890s to the 1940s, the IPA remained nearly static until the Kiel Convention in 1989, which substantially revamped the alphabet. A smaller revision took place in 1993 with the resurrection of letters for mid central vowels and the retirement 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 (extIPA) were created in 1990 and were officially adopted by the International Clinical Phonetics and Linguistics Association in 1994. They were substantially revised in 2015 with lesser changes in 2025.