Phonology is a subject in linguistics dealing with the systematic organization of sounds in human languages. Phonology is mostly concerned the study of the systems of phonemes in a language (thus also called phonemics, or phonematics) and linguistic analysis both at a level beneath the word (including syllable, onset and rime, articulatory gestures, articulatory features, mora, etc.) and at all levels of language.

Phonology can also refer to the sound system of a language. Phonology is a fundamental system a language comprised of, just like syntax and vocabulary.

Phonology is different from phonetics. Phonetics is the study of the physical production, acoustic transmission and perception of the sounds of speech, spoken language whereas phonology is concerned with the way sounds function within a language to represent meaning. Phonetics is considered to belong to descriptive linguistics, and phonology to theoretical linguistics.

The word phonology comes from Ancient Greek φωνή, phōnḗ, 'voice, sound,' and the suffix -logy (which is from Greek λόγος, lógos, 'word, speech, subject of discussion'). Definitions of the term vary. Nikolai Trubetzkoy in Grundzüge der Phonologie (1939) defines phonology as 'the study of sound pertaining to the system of language,' as opposed to phonetics, which is 'the study of sound pertaining to the act of speech' (the distinction between language and speech being basically Saussure's distinction between langue and parole). Phonology refers broadly to the subdiscipline of linguistics concerned with the sounds of language, while in more narrow terms, 'phonology proper is concerned with the function, behavior and organization of sounds as linguistic items.'[2] According to Clark et al. (2007), it means the systematic use of sound to encode meaning in any spoken human language, or the field of linguistics studying this use.

Analysis of phonemes

An important part of traditional, pre-generative schools of phonology is studying which sounds can be grouped into distinctive units within a language; these units are known as phonemes. For example, in English, the 'p' sound in pot is aspirated (pronounced [pʰ]) while that in spot is not aspirated (pronounced [p]). However, English speakers intuitively treat both sounds as variations (allophones) of the same phonological category, that is of the phoneme /p/.

Part of the phonological study of a language therefore involves looking at data (phonetic transcriptions of the speech of native speakers) and trying to deduce what the underlying phonemes are and what the sound inventory of the language is. The presence or absence of minimal pairs, as mentioned above, is a frequently used criterion for deciding whether two sounds should be assigned to the same phoneme. However, other considerations often need to be taken into account as well.

The particular contrasts which are phonemic in a language can change over time. At one time, [f] and [v], two sounds that have the same place and manner of articulation and differ in voicing only, were allophones of the same phoneme in English, but later came to belong to separate phonemes. This is one of the main factors of historical change of languages as described in historical linguistics.

The findings and insights of speech perception and articulation research complicate the traditional and somewhat intuitive idea of interchangeable allophones being perceived as the same phoneme. First, interchanged allophones of the same phoneme can result in unrecognizable words. Second, actual speech, even at a word level, is highly co-articulated, so it is problematic to expect to be able to splice words into simple segments without affecting speech perception.

Different linguists therefore take different approaches to the problem of assigning sounds to phonemes. For example, they differ in the extent to which they require allophones to be phonetically similar. There are also differing ideas as to whether this grouping of sounds is purely a tool for linguistic analysis, or reflects an actual process in the way the human brain processes a language.

Since the early 1960s, theoretical linguists have moved away from the traditional concept of a phoneme, preferring to consider basic units at a more abstract level, as a component of morphemes; these units can be called morphophonemes, and analysis using this approach is called morphophonology.

Other topics in phonology

In addition to the minimal units that can serve the purpose of differentiating meaning (the phonemes), phonology studies how sounds alternate, i.e. replace one another in different forms of the same morpheme (allomorphs), as well as, for example, syllable structure, stress, feature geometry, accent, and intonation.

Phonology also includes topics such as phonotactics (the phonological constraints on what sounds can appear in what positions in a given language) and phonological alternation (how the pronunciation of a sound changes through the application of phonological rules, sometimes in a given order which can be feeding or bleeding,[12]) as well as prosody, the study of suprasegmentals and topics such as stress and intonation.

The principles of phonological analysis can be applied independently of modality because they are designed to serve as general analytical tools, not language-specific ones. The same principles have been applied to the analysis of sign languages (see Phonemes in sign languages), even though the sub-lexical units are not instantiated as speech sounds.

Source: https://en.wikipedia.org/wiki/Phonology