In phonetics and linguistics, a phone is any distinct speech sound or gesture, regardless of whether or not the exact sound is critical to the meanings of words. In contrast, a phoneme is a speech sound that in a given language, if swapped with another phoneme, would change the meaning of the word. Phones are absolute, not specific to any language, while phonemes can only be discussed in reference to specific languages.
For example, the English words kid and kit end with two distinct phonemes, and swapping one for the other would change the word's meaning. However, the difference between the p sounds in pun (pʰ, with a puff of air) and spun (p, no puff of air) can never affect the meaning of a word in English, so they are phones and not phonemes. By contrast, swapping the same two sounds in Urdu can change one word into another: pʰal means 'fruit' and pal means 'moment' (CIIL 2008).
In the context of spoken languages, a phone is an unanalyzed sound of a language (Loos 1997). A phone is a speech segment that possesses distinct physical or perceptual properties, and serves as the basic unit of phonetic speech analysis. Phones are generally either vowels or consonants.
A phonetic transcription (based on phones) is enclosed within square brackets ([ ]), rather than the slashes (/ /) of a phonemic transcription (based on phonemes). Phones (and often phonemes also) are commonly represented using symbols of the International Phonetic Alphabet (IPA).
For example, the English word spin consists of four phones, [s], [p], [ɪ] and [n], and thus has the phonetic representation [spɪn]. The word pin has three phones; in this case the initial sound is aspirated, and so can be represented as [pʰ]; the word's phonetic representation will then be [pʰɪn]. (Precisely which features are shown in a phonetic representation will depend on whether a narrow or broad transcription is being used, and to which features the writer wishes to draw attention in the context.)
When phones are considered to be realizations of the same phoneme, they are called allophones of that phoneme (more information on the methods of making such assignments can be found under Phoneme). In English, for example, [p] and [pʰ] are considered allophones of a single phoneme, written as /p/. The phonemic transcriptions of the above two words will consequently be /spɪn/ and /pɪn/, aspiration no longer being shown, since it is not distinctive.
- Crystal, David (1971). Linguistics. Baltimore: Penguin.
- Loos, Eugene E., ed. (1997). "What is a phone?". LinguaLinks: Glossary of linguistic terms. SIL International. Retrieved 16 December 2013.
- "Urdu: Structure of Language". Language Information Service (LIS) – India. Mysore: Central Institute of Indian Languages. 2008. Retrieved 1 February 2016.