Editing Vowel (section)

==Definition==
There are two complementary definitions of vowel, one [[Phonetics|phonetic]] and the other [[Phonology|phonological]].
*In the [[phonetic]] definition, a vowel is a sound, such as the [[English language|English]] "ah" {{IPAc-en|ɑː}} or "oh" {{IPAc-en|oʊ}}, produced with an open [[vocal tract]]; it is median (the air escapes along the middle of the tongue), oral (at least some of the airflow must escape through the mouth), [[Frictionless continuant|frictionless]] and [[continuant]].<ref>{{cite book|last1=Cruttenden|first1=Alan|title=Gimson's Pronunciation of English|date=2014|publisher=Routledge|isbn=9781444183092|page=27|edition=Eighth}}</ref> There is no significant build-up of air pressure at any point above the [[glottis]]. This contrasts with [[consonant]]s, such as the English "sh" {{IPA|[ʃ]}}, which have a constriction or closure at some point along the vocal tract. 
*In the phonological definition, a vowel is defined as [[Syllable|syllabic]], the sound that forms the [[syllable nucleus|peak of a syllable]].<ref>{{cite book|last1=Cruttenden|first1=Alan|title=Gimson's Pronunciation of English|date=2014|publisher=Routledge|isbn=9781444183092|page=53|edition=Eighth}}</ref> A phonetically equivalent but non-syllabic sound is a [[semivowel]]. In [[oral language]]s, phonetic vowels normally form the peak (nucleus) of many or all syllables, whereas [[consonant]]s form the [[syllable onset|onset]] and (in languages that have them) [[syllable coda|coda]]. Some languages allow other sounds to form the nucleus of a syllable, such as the [[syllabic consonant|syllabic]] (i.e., vocalic) ''l'' in the English word ''table'' {{IPA|[ˈtʰeɪ.bl̩]}} (when not considered to have a weak vowel sound: {{IPA|[ˈtʰeɪ.bəl]}}) or the syllabic ''r'' in the [[Serbo-Croatian]] word ''vrt'' {{IPA|[ʋr̩̂t]}} "garden".

The phonetic definition of "vowel" (i.e. a sound produced with no constriction in the vocal tract) does not always match the phonological definition (i.e. a sound that forms the peak of a syllable).<ref>Laver, John (1994) ''Principles of Phonetics'', Cambridge: Cambridge University Press, p. 269.</ref> The [[approximant]]s {{IPA|[j]}} and {{IPA|[w]}} illustrate this: both are without much of a constriction in the vocal tract (so phonetically they seem to be vowel-like), but they occur at the onset of syllables (e.g. in "yet" and "wet") which suggests that phonologically they are consonants. A similar debate arises over whether a word like ''bird'' in a [[Rhotic consonant|rhotic]] dialect has an [[r-colored vowel]] {{IPA|/ɝ/}} or a syllabic consonant {{IPA|/ɹ̩/}}. The American linguist [[Kenneth Pike]] (1943) suggested the terms "'''vocoid'''" for a phonetic vowel and "vowel" for a phonological vowel,<ref>Crystal, David (2005) ''A Dictionary of Linguistics & Phonetics (Fifth Edition)'', Maldern, MA/Oxford: Blackwell, p. 494.</ref> so using this terminology, {{IPA|[j]}} and {{IPA|[w]}} are classified as vocoids but not vowels. However, Maddieson and Emmory (1985) demonstrated from a range of languages that semivowels are produced with a narrower constriction of the vocal tract than vowels, and so may be considered consonants on that basis.<ref>{{SOWL|323}}</ref> Nonetheless, the phonetic and phonemic definitions would still conflict for the syllabic /l/ in ''table'' or the syllabic nasals in ''button'' and ''rhythm''.