Phoneme

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This article is about the speech unit. For the JavaME library, see phoneME (software).

In human language, a phoneme is the smallest posited structural unit that distinguishes meaning. Phonemes are not the physical segments themselves, but, in theoretical terms, cognitive abstractions or categorizations of them.

An example of a phoneme is the /t/ sound in the words tip, stand, water, and cat. (In transcription, phonemes are placed between slashes, as here.) These instances of /t/ are considered to fall under the same sound category despite the fact that in each word they are pronounced somewhat differently. The difference may not even be audible to native speakers. That is, a phoneme may encompass several recognizably different speech sounds, called phones. In our example, the /t/ in tip is aspirated, [tʰ], while the /t/ in stand is not, [t]. (In transcription, speech sounds that are not phonemes are placed in brackets, as here.) In many languages, such as Korean and Spanish, these phones are different phonemes: For example, /tol/ is "stone" in Korean, whereas /tʰol/ is "grain of rice". In Spanish, there is no aspirated [tʰ], but the phone in American English writer is similar to the Spanish r /ɾ/ and contrasts with Spanish /t/.

Phones that belong to the same phoneme, such as [t] and [tʰ] for English /t/, are called allophones. A common test to determine whether two phones are allophones or separate phonemes relies on finding minimal pairs: words that differ by only the phones in question. For example, the words tip and dip illustrate that [t] and [d] are separate phonemes, /t/ and /d/, in English, whereas the lack of such a contrast in Korean (/tʰata/ is pronounced [tʰada], for example) indicates that in this language they are allophones of a phoneme /t/.

In sign languages, the basic elements of gesture and location were formerly called cheremes (or cheiremes), but general usage changed to phoneme. Tonic phonemes are sometimes called tonemes, and timing phonemes chronemes.

Some linguists (such as Roman Jakobson) consider phonemes to be further decomposable into features, such features being the true minimal constituents of language. Features overlap each other in time, as do suprasegmental phonemes in oral language and many phonemes in sign languages.

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[edit] Background and related ideas

In ancient India, the Sanskrit grammarian Pāṇini (c. 520–460 BC), in his text of Sanskrit grammar, the Shiva Sutras, originated the concepts of the phoneme, the morpheme and the root. The Shiva Sutras, traditionally prefaced to the Aṣṭādhyāyī, presents a system of phonemic notation in fourteen terse aphorisms. This notational system introduces different clusters of phonemes that serve special roles in the morphology of Sanskrit, and are referred to throughout the text.

Around the 1st century CE, the definitions of phoneme (oliyam) and alphabet (ezuththu) were discussed in the Tolkāppiyam concerning the Tamil language.

The term phonème was reportedly first used by Dufriche-Desgenettes in 1873, but it referred to only a sound of speech. The term phoneme as an abstraction was developed by the Polish linguist Jan Niecisław Baudouin de Courtenay and his student Mikołaj Kruszewski during 1875-1895. The term used by these two was fonema, the basic unit of what they called psychophonetics. The concept of the phoneme was elaborated in the works of Nikolai Trubetzkoi and other of the Prague School (during the years 1926-1935), as well as in that of structuralists like Ferdinand de Saussure, Edward Sapir, and Leonard Bloomfield. Later, it was also used in generative linguistics, most famously by Noam Chomsky and Morris Halle, and remains central to many accounts of the development of modern of phonology. As a theoretical concept or model, though, it has been supplemented and even replaced by others.

Some languages make use of pitch for phonemic distinction. In this case, the tones used are called tonemes. Some languages distinguish words made up of the same phonemes (and tonemes) by using different durations of some elements, which are called chronemes. However, not all scholars working on languages with distinctive duration use this term.

Usually, long vowels and consonants are represented either by a length indicator or doubling of the symbol in question.

In sign languages, phonemes may be classified as Tab (elements of location, from Latin tabula), Dez (the hand shape, from designator), Sig (the motion, from signation), and with some researchers, Ori (orientation). Facial expressions and mouthing are also phonemic.

[edit] Notation

A transcription that only indicates the different phonemes of a language is said to be phonemic. Such transcriptions are enclosed within virgules (slashes), / /; these show that each enclosed symbol is claimed to be phonemically meaningful. On the other hand, a transcription that indicates finer detail, including allophonic variation like the two English L's, is said to be phonetic, and is enclosed in square brackets, [ ].

The common notation used in linguistics employs virgules (slashes) (/ /) around the symbol that stands for the phoneme. For example, the phoneme for the initial consonant sound in the word "phoneme" would be written as /f/. In other words, the graphemes are <ph>, but this digraph represents one sound /f/. Allophones, more phonetically specific descriptions of how a given phoneme might be commonly instantiated, are often denoted in linguistics by the use of diacritical or other marks added to the phoneme symbols and then placed in square brackets ([ ]) to differentiate them from the phoneme in slant brackets (/ /). The conventions of orthography are then kept separate from both phonemes and allophones by the use of angle brackets < > to enclose the spelling.

The symbols of the International Phonetic Alphabet (IPA) and extended sets adapted to a particular language are often used by linguists to write phonemes of oral languages, with the principle being one symbol equals one categorical sound. Due to problems displaying some symbols in the early days of the Internet, systems such as X-SAMPA and Kirshenbaum were developed to represent IPA symbols in plain text. As of 2004, any modern web browser can display IPA symbols (as long as the operating system provides the appropriate fonts), and we use this system in this article.

There are 2 published set of phonemic symbols for sign language: SignWriting and Stokoe notation. SignWriting is capable of writing any sign language and is currently used in over 38 countries. People in these countries use SignWriting on a daily basis as a natural writing system for education and recreation. Stokoe notation is used for linguistic research and was originally developed for American Sign Language. Stokoe notation has since been applied to British Sign Language by Kyle and Woll, and to Australian Aboriginal sign languages by Adam Kendon.

[edit] Examples

Examples of phonemes in the English language would include sounds from the set of English consonants, like /p/ and /b/. These two are most often written consistently with one letter for each sound. However, phonemes might not be so apparent in written English, such as when they are typically represented with combined letters, called digraphs, like <sh> (pronounced /ʃ/) or <ch> (pronounced /tʃ/).

To see a list of the phonemes in the English language, see IPA for English.

Two sounds that may be allophones (sound variants belonging to the same phoneme) in one language may belong to separate phonemes in another language or dialect. In English, for example, /p/ has aspirated and non-aspirated allophones:aspirated as in /pɪn/, and non-aspirated as in /spɪn/. However, in many languages (e. g. Chinese), aspirated /pʰ/ is a phoneme distinct from unaspirated /p/. As another example, there is no distinction between [r] and [l] in Japanese; there is only one /r/ phoneme, though it has various allophones that can sound more like [l], [ɾ], or [r] to English speakers. The sounds [z] and [s] are distinct phonemes in English, but allophones in Spanish. The sounds [n] (as in run) and [ŋ] (as in rung) are phonemes in English, but allophones in Italian and Spanish.

An important phoneme is the chroneme, a phonemically-relevant extension of the duration a consonant or vowel. Some languages or dialects such as Finnish or Japanese allow chronemes after both consonants and vowels. Others, like Italian or Australian English use it after only one (in the case of Italian, consonants; in the case of Australian, vowels).

[edit] Restricted phonemes

A restricted phoneme is a phoneme that can only occur in a certain environment: There are restrictions as to where it can occur. English has several restricted phonemes:

  • /ŋ/, as in sing, occurs only at the end of a syllable, never at the beginning (in many other languages, such as Swahili or Thai, /ŋ/ can appear word-initially).
  • /h/ occurs only before vowels and at the beginning of a syllable, never at the end (a few languages, such as Arabic, or Romanian allow /h/ syllable-finally).
  • In many American dialects with the cot-caught merger, /ɔ/ occurs only before /r/, /l/, and in the diphthong /ɔɪ/.
  • In non-rhotic dialects, /r/ can only occur before a vowel, never at the end of a word or before a consonant.
  • Under most interpretations, /w/ and /j/ occur only before a vowel, never at the end of a syllable. However, many phonologists interpret a word like boy as either /bɔɪ/ or /bɔj/.

[edit] Neutralization, archiphoneme, underspecification

Main article: Underspecification

Phonemes that are contrastive in certain environments may not be contrastive in all environments. In the environments where they don't contrast, the contrast is said to be neutralized.

In English there are three nasal phonemes, /m, n, ŋ/, as shown by the minimal triplet,

/sʌm/ sum
/sʌn/ sun
/sʌŋ/ sung

However, with rare exceptions, these sounds are not contrastive before plosives such as /p, t, k/ within the same morpheme. Although all three phones appear before plosives, for example in limp, lint, link, only one of these may appear before each of the plosives. That is, the /m, n, ŋ/ distinction is neutralized before each of the plosives /p, t, k/:

  • Only /m/ occurs before /p/,
  • only /n/ before /t/, and
  • only /ŋ/ before /k/.

Thus these phonemes are not contrastive in these environments, and according to some theorists, there is no evidence as to what the underlying representation might be. If we hypothesize that we are dealing with only a single underlying nasal, there is no reason to pick one of the three phonemes /m, n, ŋ/ over the other two.

(In some languages there is only one phonemic nasal anywhere, and due to obligatory assimilation, it surfaces as [m, n, ŋ] in just these environments, so this idea is not as far-fetched as it might seem at first glance.)

In certain schools of phonology, such a neutralized distinction is known as an archiphoneme (Nikolai Trubetzkoy of the Prague school is often associated with this analysis.). Archiphonemes are often notated with a capital letter. Following this convention, the neutralization of /m, n, ŋ/ before /p, t, k/ could be notated as |N|, and limp, lint, link would be represented as |lɪNp, lɪNt, lɪNk|. (The |pipes| indicate underlying representation.) Other ways this archiphoneme could be notated are |m-n-ŋ|, {m, n, ŋ}, or |n*|.

Another example from American English is the neutralization of the plosives /t, d/ following a stressed syllable. Phonetically, both are realized in this position as [ɾ], a voiced alveolar flap. This can be heard by comparing writer with rider (for the sake of simplicity, Canadian raising is not taken into account).

[ɻaɪˀt] write
[ɻaɪd] ride

with the suffix -er:

[ˈɻaɪɾɚ] writer
[ˈɻaɪɾɚ] rider

Thus, one cannot say whether the underlying representation of the intervocalic consonant in either word is /t/ or /d/ without looking at the unsuffixed form. This neutralization can be represented as an archiphoneme |D|, in which case the underlying representation of writer or rider would be |'ɻaɪDɚ|.

Another way to talk about archiphonemes involves the concept of underspecification: phonemes can be considered fully specified segments while archiphonemes are underspecified segments. In Tuvan, phonemic vowels are specified with the features of tongue height, backness, and lip rounding. The archiphoneme |U| is an underspecified high vowel where only the tongue height is specified.

phoneme/
archiphoneme		 height backness roundedness
/i/ high front unrounded
/ɯ/ high back unrounded
/u/ high back rounded
|U| high

Whether |U| is pronounced as front or back and whether rounded or unrounded depends on vowel harmony. If |U| occurs following a front unrounded vowel, it will be pronounced as the phoneme /i/; if following a back unrounded vowel, it will be as an /ɯ/; and if following a back rounded vowel, it will be an /u/. This can been seen in the following words:

-|Um| 'my' (the vowel of this suffix is underspecified)
|idikUm| → [idikim] 'my boot' (/i/ is front & unrounded)
|xarUm| → [xarɯm] 'my snow' (/a/ is back & unrounded)
|nomUm| → [nomum] 'my book' (/o/ is back & rounded)

Not all phonologists accept the concept of archiphonemes. Many doubt that it reflects how people process language or control speech, and some argue that archiphonemes add unnecessary complexity.

[edit] Phonological extremes

Of all the sounds that a human vocal tract can create, different languages vary considerably in the number of these sounds that are considered to be distinctive phonemes in the speech of that language. Ubyx and Arrernte have only two phonemic vowels, while at the other extreme, the Bantu language Ngwe has fourteen vowel qualities, twelve of which may occur long or short, for twenty-six oral vowels, plus six nasalized vowels, long and short, for thirty-eight vowels; while !Xóõ achieves thirty-one pure vowels—not counting vowel length, which it also has—by varying the phonation. Rotokas has only six consonants, while !Xóõ has somewhere in the neighborhood of seventy-seven, and Ubyx eighty-one. French has no phonemic tone or stress, while several of the Kam-Sui languages have nine tones, and one of the Kru languages, Wobe, has been claimed to have fourteen, though this is disputed. The total phonemic inventory in languages varies from as few as eleven in Rotokas to as many as 112 in !Xóõ (including four tones). These may range from familiar sounds like [t], [s], or [m] to very unusual ones produced in extraordinary ways (see: Click consonant, phonation, airstream mechanism). The English language itself uses a rather large set of thirteen to twenty-two vowels, including diphthongs, though its twenty-two to twenty-six consonants are close to average. (There are twenty-one consonant and five vowel letters in the English alphabet, but this does not correspond to the number of consonant and vowel sounds.)

The most common vowel system consists of the five vowels /i/, /e/, /a/, /o/, /u/. The most common consonants are /p/, /t/, /k/, /m/, /n/. Very few languages lack one of these: Arabic lacks /p/, standard Hawaiian lacks /t/, Mohawk lacks /p/ and /m/, Hupa lacks both /p/ and a simple /k/, colloquial Samoan lacks /t/ and /n/, while Rotokas and Quileute lack /m/ and /n/. While most of languages missing sounds have very small inventories, Arabic, Quileute, and Hupa have quite complex consonant systems.

[edit] See also

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