The International Phonetic Alphabet (IPA) is an alphabetic system developed with the intention of enabling students and linguists to learn and record the pronunciation of languages accurately, thereby avoiding the confusion of inconsistent, conventional spellings and a multitude of individual transcription systems. One aim of the IPA was to provide a unique symbol for each distinctive sound in a language—that is, every sound, or phoneme, that serves to distinguish one word from another.
IPA primarily uses Roman characters. Diacritics are used for fine distinctions in sounds and to show nasalization of vowels, length, stress, and tones. The concept of IPA was first broached by Otto Jespersen in a letter to Paul Passy of the International Phonetic Association and was developed by A.J. Ellis, Henry Sweet, Daniel Jones, and Passy in the late 19th century.