Dissimilation
In phonology, particularly within historical linguistics, dissimilation is a phenomenon whereby similar consonants or vowels in a word become less similar or elided. In English, dissimilation is particularly common with liquid consonants such as and when they occur in a sequence. The phenomenon is often credited to horror aequi, the principle that language users avoid repetition of identical linguistic structures.
Examples
Dropped initial /r/ in /r..r/ sequence (r-deletion)
When an sound occurs along with another in the middle of a word in rhotic dialects of English, the most weakly-stressed tends to drop out, as in "" for berserk, "" for surprise, "" for particular, and "" for governor. This does not affect the pronunciation of government, which has only one, but English government tends to be pronounced "", dropping the first n. Nor does this phenomenon affect the unstressed syllable in words like surfer or brother, since they come at the end of the word.In English, r-deletion occurs when a syllable is unstressed and may drop out altogether, as in "" for deteriorate and "" for temperature, a process called haplology. When the is found in, it may change to — February → ', which has been explained by phonotactic factors or alternatively by morphological analogy with more common sequences such as January. nucular, which may have arisen through an analogous process.
r-deletion is not universally applied in regard to primary and tertiary stress. For example, forward is typically affected, but foreword and Harvard are not. Forewords lack of r''-deletion may be due to its lower-frequency usage, but this inconsistency may also indicate that the process is still in flux and not yet fully established.
Dissimilation of /l..l/ to /r..l/
An example of a relatively old case of phonetic dissimilation artificially undone in the spelling is English , whose standard pronunciation is in North-American English or in RP. It was formerly spelt coronel and is a borrowing from French, which arose as a result of dissimilation from Italian.Dissimilation of /r..r/ to /l..r/
- Latin > Old French , which gave rise to the English .
Causes
There are several hypotheses on the cause of dissimilation. According to John Ohala, listeners are confused by sounds with long-distance acoustic effects. In the case of English, rhoticization spreads across much of the word: in rapid speech, many of the vowels may sound as if they had an r. It may be difficult to tell whether a word has one source of rhoticity or two. When there are two, a listener might wrongly interpret one as an acoustic effect of the other, and so mentally filter it out.This factoring out of coarticulatory effects has been experimentally replicated. For example, Greek derives from an earlier *. When test subjects are asked to say the * form in casual speech, the aspiration from both consonants pervades both syllables, making the vowels breathy. Listeners hear a single effect, breathy voiced vowels, and attribute it to one rather than both of the consonants, as they assume the breathiness on the other syllable is a long-distance coarticulatory effect, thus replicating the historical change in the Greek word.
If Ohala is correct, one might expect to find dissimilation in other languages with sounds that frequently cause long-distance effects, such as nasalization and pharyngealization.
Types
Dissimilation, like assimilation, may involve a change in pronunciation relative to a segment adjacent to the affected segment or at a distance, and may involve a change relative to a preceding or a following segment. As with assimilation, dissimilation is much more common than dissimilation, but unlike assimilation, most dissimilation is triggered by non-contiguous segments. Also, while many kinds of assimilation have the character of a sound law, few dissimilations do; most are accidents that befall a particular lexical item.Anticipatory dissimilation
Anticipatory dissimilation at a distance :- Latin *medio-diēs became merīdiēs. Latin venēnum "poison" > Italian veleno. This category includes a rare example of a systematic sound law, the dissimilation of aspirates in Greek and Sanskrit known as Grassmann's Law: *thi-thē-mi > Greek , *phakhu > Greek , *sekhō > *hekhō > Greek . Some apparent cases are problematic, as in English "eksetera" for etcetera, which may be contamination from the numerous forms in eks-, though the common misspelling "ect." implies dissimilation.
- The change from fricative to stop articulation in a sequence of fricatives may belong here: German sechs . In Sanskrit, in any original sequence of two sibilants the first became a stop : root vas-, fut. vas-sya- > vatsya-; *wiś-s > *viťś > *viṭṣ > viṭ ; *wiś-su locative pl. > *viṭṣu > vikṣu. English amphitheater is very commonly pronounced "", but this may be explained by spelling pronunciation. Russian конфорка is from Dutch komfoor.
Lag dissimilation
Lag dissimilation at a distance :- English purple is in medieval English as purpul and purpure and comes from classical Latin purpura with dissimilation of to. Latin rārus > Italian rado. Cardamom is commonly pronounced cardamon. In Middle English, in some words ending in -n preceded by a coronal consonant the -n changed to -m: seldom, random, venom. English marble is ultimately from Latin marmor. Russian февраль is from Latin Februārius.
- In Spanish, interchanges between and are common; for a list, see. In Basque, dissimilation is frequent as well.
- Latin hominem > Old Spanish omne > omre > Spanish hombre
- Latin nomine > nomre > Spanish nombre
- English chimney > chimley
- Proto-Slavic *svobodà > Slovak sloboda
- In Irish, many dialects regularly change the sequence to
Paradigmatic dissimilation
When, through sound change, elements of a grammatical paradigm conflate in a way not easily remedied by rewording, the forms may dissimilate. For example, in modern Korean the vowels and are merging for many people in Seoul, and concurrently the second-person pronoun 네 is shifting to 니 to avoid confusion with the first-person pronoun 내 .Similarly, it appears that English she, historically heo, may have acquired its modern sh form through dissimilation from he, though it is unclear whether the mechanism was idiosyncratic sound change of heo or substitution for heo of the feminine demonstrative pronoun seo.