Phonological Rules and Processes

Phonological processes were first systematically studied in the nineteenth century under the rubric of sound laws relating the various Indo-European languages. In the twentieth century, attention shifted to a synchronic perspective, prompted by observations such as Edward SAPIR's that as part of their grammatical competence mature speakers unconsciously and effortlessly assign (sometimes radically) different pronunciations to a lexical item drawn from memory and inserted in different grammatical or prosodic contexts. For example, in the pronunciation of the word átom American English speakers "flap" the intervocalic consonant to [] and reduce the unstressed vowel to schwa [] so that it merges with Adam: [ m]. The underlying phonemes emerge when the stress is shifted under affixation: atóm-ic [th"am- Ik]. Processes also figure in the neutralizations found in child language such as the loss of the tongue-tip articulation of r so that room merges with womb.

Phonological processes fall into two broad categories: sound change and prosodic grouping. We briefly illustrate each type. In in-articulate versus im-possible the prefixal nasal assimilates the labial feature of the [p] thereby changing from [n] to [m]. Dissimilation alters neighboring sounds that share the same feature so that they become more distinct from one another (see DISTINCTIVE FEATURES). For example, the vocalic nucleus and offglide comprising the [au] diphthong of how share a retracted tongue position in most English dialects. In broad Australian English the nucleus is fronted to the [æ] vowel of cat: h[æu]. Assimilation and dissimilation are subject to a strict locality condition requiring that they apply in the context of the closest sound with the appropriate feature. The phonological features that define a sound are also subject to deletion and insertion: the former typically operates in prosodically weak contexts (reduction of unstressed vowels to schwa in át[ ]m but [ ]tóm-ic) and the latter in strong contexts (aspiration of [t] before stress in a[th]ómic).

Processes of prosodic grouping include the organization of phonemes into syllables. In English a consonant cluster such as [rt] easily combines with the preceding vowel into a single syllable: monosyllabic mart. But in order to syllabify the inverse cluster [tr], a helping schwa is required: disyllabic me.t[ ]r (cf. metr-ic). Languages such as Japanese have simpler syllabic structures that bar syllable-internal consonant clusters and place rigid restrictions on syllable-final consonants. Accordingly, the [rt] cluster in a loanword such as French courte [kurt] 'short' receives two extra syllables when it is adapted into Japanese: kuruto (Shinohara 1997). At the next level of prosodic organization, syllables are grouped into strong-weak (trochaic) or weak-strong (iambic) rhythmic units known as metrical feet. Native Australian languages impose trochaic rhythm so that words have a canonical SsSsSs . . . syllabic structure in comparison to the iambic grouping sSsSsS . . . found in many Native American languages. English has trochaic grouping as shown by the strong-weak template imposed on nickname formation: Elízabeth shortens to Ss Lísa; sS Elí is impossible.

Some linguists (e.g., Stampe 1979) distinguish between "processes" that reflect phonetically motivated limitations on which sounds can appear where in pronunciation and more arbitrary and conventional "rules" that are typically restricted to particular morphological or lexical contexts such as the voicing of [f] in the plural of leaf: leaves but reefs (*reeves) and verbal he leafs (*leaves) through the paper). A plausible but unsubstantiated hypothesis is that rules relate different lexical items stored in memory while processes operate online.

Phonological processes are often phonetically motivated, seeming either to enhance the perceptibility of a sound, especially in "strong" contexts or more formal speaking styles (aspiration of prestressed [t] in a[t h]ómic), or to minimize articulatory gestures, especially in "weak" contexts or fast tempos (flapping of the stop and reduction of the unstressed vowel of átom ["æ m]). Besides a typology based on their formal properties, phonological processes are also usefully viewed as different solutions to a common phonetic difficulty. For example, the transition from the nasal to the fricative in the consonant cluster of dense is relatively complex because it requires synchronization of two independent gestures: raising the velum to shut off nasal airflow and shifting the tongue tip from a closure to a constriction. Common responses include insertion of a transitional stop den[t]se (to rhyme with dents) or deletion of the tongue-tip closure d[ ~]s. An example from prosody is provided by the widespread tendency to avoid syllables beginning with a vowel. When morphological or syntactic rules juxtapose vowels, a variety of processes come into play to avoid a syllable break between the vowels. These include deletion of one of the vowels (Slavic), contraction of the vowels into a diphthong (Polynesian) or long vowel (Sanskrit), or insertion of a consonantal onset (British English intrusive [r] as in the idea [r] is).

Processes are characteristically myopic in the sense that in solving one phonetic problem they often create another. Popular London (Cockney) deletion of initial [h] creates a vowel cluster with the indefinite article ("a hedge" [d) -- a situation that is otherwise avoided by substitution of the an allomorph (cf. "an edge" [n d]; Wells 1982). To take another example (data from Bethin 1992), in Polish [n] assimilates the place of articulation of a following velar: ba[ ]k 'bank'. In the Southwestern dialect, the process is extended to clusters arising from the deletion of a weak vowel, whereas in the Northeastern dialect, such derived nk clusters remain unassimilated: ganek 'porch', ga[ ]ka SW versus ga[n]ka NE genitive singular. Many phonologists (e.g., Halle 1962) conclude from examples like this that processes apply in a linear sequence: in the Southwestern dialect, vowel deletion precedes nasal assimilation, whereas in the Northeastern dialect, nasal assimilation precedes vowel deletion (and so sees /ganek+a/ at its point of application). An alternative interpretation (Donegan and Stampe 1979) sees all processes as applying simultaneously to the input with each given the option to iterate (Southwestern) or not (Northeastern).

Although myopic, phonological processes are typically not self-defeating in the sense of recreating the same problem they are called upon to solve. An example is provided by the liquid [l,r] dissimilation inherited from Latin (Steriade 1995), in which the suffixal [l] of nav-al, fat-al, mor-al is turned into [r] when the stem contains an [l]: stell-ar, lun-ar, column-ar, nucle-ar. The process systematically blocks when an [r] intervenes between the suffixal and stem [l]"s: flor-al, plur-al, later-al. If the point of the change is to avoid successive identical liquids, an output such as *flor-ar is no better than the input flor-al and hence the process is suspended.

Providing empirical substantiation to the notion "phonetic motivation" as well as determining the principles that underlie the interaction of rules and constraints remain outstanding research objectives.

See also

Additional links

-- Michael Kenstowicz


Bethin, C. (1992). Polish Syllables. Columbus, OH: Slavica Publishers.

Donegan, P., and D. Stampe. (1979). The study of natural phonology. In D. Dinnsen, Ed., Current Approaches to Phonological Theory. Bloomington, IN: Indiana University Press, pp. 126-173.

Halle, M. (1962). Phonology in generative grammar. Word 18:54-72.

Makkai, V. B. (1972). Phonological Theory: Evolution and Current Practice. New York: Holt.

Sapir, E. (1925). Sound patterns in language. Language 1:37-51. Reprinted in Makkai 1972, pp. 13 - 21.

Sapir, E. (1933). The psychological reality of phonemes. Reprinted in Makkai 1972, pp. 22-31.

Shinohara, S. (1997). Analyse phonologique de l"adaptation japonaise de mots étrangers. Paris: Université de la Sorbonne Nouvelle, Paris 3.

Stampe, D. (1979). A Dissertation on Natural Phonology. New York: Garland.

Steriade, D. (1995). Underspecification and markedness. In J. Goldsmith, Ed., Handbook of Phonological Theory. Oxford: Blackwell, pp. 114-174.

Wells, J. (1982). Accents of English. Cambridge: Cambridge University Press.

Further Readings

Archangeli, D. and D. Pulleyblank. (1993). Grounded Phonology. Cambridge, MA: MIT Press.

Greenberg, J. (1978). Universals of Human Language. Stanford, CA: Stanford University Press.

Kenstowicz, M. (1994). Phonology in Generative Grammar. Oxford: Blackwell.