The International Phonetic Alphabet
A notation system that gives every speech sound one unambiguous symbol, used by dictionaries, language learners, and speech scientists.
The International Phonetic Alphabet (IPA) is a standardized notation system for the sounds of human speech, designed so that each symbol represents one distinctive sound and each sound has exactly one symbol. It was created in 1886 by the International Phonetic Association and has been revised regularly since, most recently in 2005. Because ordinary spelling is notoriously inconsistent — English "ough" has many pronunciations, and different languages use the same letters differently — the IPA provides a language-independent way to write pronunciation.
The alphabet organizes consonants by three properties: place of articulation (where the airstream is constricted, from the lips to the glottis), manner of articulation (how it is constricted: plosive, nasal, fricative, approximant, and so on), and voicing (whether the vocal folds vibrate). A few examples from English:
| Symbol | Description | In English |
|---|---|---|
| /p/ | voiceless bilabial plosive | pat |
| /b/ | voiced bilabial plosive | bat |
| /f/ | voiceless labiodental fricative | fat |
| /θ/ | voiceless dental fricative | think |
| /ʃ/ | voiceless postalveolar fricative | ship |
| /ŋ/ | velar nasal | sing |
Vowels are described by tongue height, tongue backness, and lip rounding, and are plotted on a vowel quadrilateral — /i/ (as in "see") is high and front, /u/ (as in "too") is high and back, /æ/ (as in "cat") is low and front. Diacritics add detail: aspiration, nasalization, length marks, and tone marks extend the basic symbols. A distinction is drawn between broad transcription, in slashes and containing only phonemic contrasts, and narrow transcription, in square brackets and recording phonetic detail — /kæt/ versus [kʰæt] for "cat."
The IPA is the working notation of phonetics and phonology, lexicography, language teaching, speech pathology, dialectology, and speech technology: dictionaries transcribe pronunciations with it, field linguists document unwritten languages with it, and speech-recognition and synthesis systems use it to label acoustic data. It also has limitations that users should know. It is an abstraction — real pronunciations vary continuously and across dialects, so a transcription is a convention, not a measurement — and it favors the segmental, consonant-and-vowel structure that not every language displays with equal ease. For its core purpose, however, an unambiguous notation for speech sounds, it remains the standard tool of the discipline.
Tags
linguistics phonetics writing systems