INTERNATIONAL PHONETIC ALPHABET, short form IPA. An ALPHABET developed by the International Phonetic Association to provide suitable symbols for the sounds of any language. The symbols are based on the Roman alphabet, with further symbols created by inverting or reversing Roman letters or taken from the Greek alphabet. The main characters are supplemented when necessary by diacritics. The first version of the alphabet was developed in the late 19c by A. E. Ellis, Paul Passy, Henry Sweet, and Daniel JONES from a concept proposed by Otto Jespersen. It has been revised from time to time, most recently in 1989 (see accompanying charts). The IPA is sufficiently rich to label the phonemes of any language and to handle the contrasts between them, but its wide range of exotic symbols and diacritics makes it difficult and expensive for printers and publishers to work with. As a result, modifications are sometimes made for convenience and economy, for example in ELT learners' dictionaries. Phoneme symbols are used in phonemic transcription, either to provide a principled method of transliterating non-Roman alphabets (such as Russian, Arabic, Chinese), or to provide an alphabet for a previously unwritten language. The large number of diacritics makes it possible to mark minute shades of sound as required for a narrow phonetic transcription. The alphabet has not had the success that its designers hoped for, in such areas as the teaching of languages (especially English) and SPELLING REFORM. It is less used in North America than elsewhere, but is widely used as a pronunciation aid for EFL and ESL, especially by British publishers and increasingly in British dictionaries of English. See ENGLISH PRONOUNCING DICTIONARY, LANGUAGE TEACHING, LEARNER'S DICTIONARY, PHONETIC TRANSCRIPTION, SPEECH, RESPELLING, WRITING.