   #copyright

Vowel

2007 Schools Wikipedia Selection. Related subjects: Linguistics

                          Manners of articulation
   Obstruent
   Click
   Plosive
   Ejective
   Implosive
   Affricate
   Fricative
   Sibilant
   Sonorant
   Nasal
   Flaps/Tap
   Trill
   Approximant
   Liquid
   Vowel
   Semivowel
   Lateral
   This page contains phonetic information in IPA, which may not display
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   In phonetics, a vowel is a sound in spoken language that is
   characterized by an open configuration of the vocal tract so that there
   is no build-up of air pressure above the glottis. This contrasts with
   consonants, which are characterized by a constriction or closure at one
   or more points along the vocal tract. A vowel is also understood to be
   syllabic: an equivalent open but non-syllabic sound is called a
   semivowel.

   In all languages, vowels form the nucleus or peak of syllables, whereas
   consonants form the onset and (in languages which have them) coda.
   However, some languages also allow other sounds to form the nucleus of
   a syllable, such as the syllabic l in the English word table [ˈteɪ.bl̩]
   (the stroke under the l indicates that it is syllabic; the dot
   separates syllables), or the r in the Serbian word vrba [vr̩.ba]
   "willow".

   The word vowel comes from the Latin word vocalis, meaning "speaking",
   because in most languages words and thus speech are not possible
   without vowels.

Articulation

   Vowels
   Edit - 2× Front N.-front Central N.-back Back
   Close

             i •  y
             ɨ •  ʉ
             ɯ •  u
             ɪ •  ʏ
             •  ʊ
             e •  ø
             ɘ •  ɵ
             ɤ •  o
             ə
             ɛ •  œ
             ɜ •  ɞ
             ʌ •  ɔ
             æ
             ɐ
             a •  ɶ
             ɑ •  ɒ
   Near-close
   Close-mid
   Mid
   Open-mid
   Near-open
   Open
   Where symbols appear in pairs, the one to the right
   represents a rounded vowel.
   X-rays of Daniel Jones' [i, u, a, ɑ].
   Enlarge
   X-rays of Daniel Jones' [i, u, a, ɑ].

   The articulatory features that distinguish different vowels in a
   language are said to determine the vowel's quality. Daniel Jones
   developed the cardinal vowel system to describe vowels in terms of the
   common features height (vertical dimension), backness (horizontal
   dimension) and roundedness (lip position). These three parameters are
   indicated in the schematic IPA vowel diagram on the right. There are
   however still more possible features of vowel quality, such as the
   velum position (nasality), type of vocal fold vibration (phonation),
   and tongue root position.

Height

   Height refers to the vertical position of the tongue relative to either
   the roof of the mouth or the aperture of the jaw. In high vowels, such
   as [i] and [u], the tongue is positioned high in the mouth, whereas in
   low vowels, such as [a], the tongue is positioned low in the mouth.
   Sometimes the terms open and close are used as synonyms for low and
   high for describing vowels. The International Phonetic Alphabet
   identifies seven different vowel heights, although no known language
   distinguishes all seven:
     * close vowel (high vowel)
     * near-close vowel
     * close-mid vowel
     * mid vowel
     * open-mid vowel
     * near-open vowel
     * open vowel (low vowel)

   It may be that some varieties of German have five contrasting vowel
   heights independently of length or other parameters. The Bavarian
   dialect of Amstetten has thirteen long vowels, reported to distinguish
   four heights (close, close-mid, mid, and near-open) each among the
   front unrounded, front rounded, and back rounded vowels, plus an open
   central vowel: /i e ɛ̝ æ̝/, /y ø œ̝ ɶ̝/, /u o ɔ̝ ɒ̝/, /a/. Otherwise,
   the usual limit on the number of vowel heights is four.

   The parameter of vowel height appears to be the primary feature of
   vowels cross-linguistically in that all languages use height
   contrastively. No other parameter, such as front-back or
   rounded-unrounded (see below), is used in all languages. Some languages
   use only height to distinguish vowels.

Backness

   Backness refers to the horizontal tongue position during the
   articulation of a vowel relative to the back of the mouth. In front
   vowels, such as [i], the tongue is positioned forward in the mouth,
   whereas in back vowels, such as [u], the tongue is positioned towards
   the back of the mouth. The International Phonetic Alphabet identifies
   five different degrees of vowel backness, although no known language
   distinguishes all five:
     * front vowel
     * near-front vowel
     * central vowel
     * near-back vowel
     * back vowel

   The highest number of contrastive degrees of backness is 3.

Roundedness

   Roundedness refers to whether the lips are rounded or not. In most
   languages, roundedness is a reinforcing feature of mid to high back
   vowels, and not distinctive. Usually the higher a back vowel, the more
   intense the rounding. However, some languages treat roundedness and
   backness separately, such as French and German (with front rounded
   vowels), most Uralic languages ( Estonian has a rounding contrast for
   /o/ and front vowels), Turkic languages (with an unrounded /u/),
   Vietnamese (with back unrounded vowels), and Korean (with a contrast in
   both front and back vowels).

   Nonetheless, even in languages such as German and Vietnamese, there is
   usually some phonetic correlation between rounding and backness: front
   rounded vowels tend to be less front than front unrounded vowels, and
   back unrounded vowels tend to be less back than back rounded vowels.
   That is, the placement of unrounded vowels to the left of rounded
   vowels on the IPA vowel chart is reflective of their typical position.

   Different kinds of labialization are also possible. The Japanese /u/,
   for example, is not rounded like English /u/, where the lips are
   protruded (or pursed), but neither are the lips spread to the sides as
   they are for unrounded vowels. Rather, they are compressed in both
   directions, leaving a slot between the lips for the air to escape. (See
   Vowel roundedness for illustrations.) Swedish and Norwegian are two of
   the few languages where this feature is contrastive, having both
   protruded-lip and compressed-lip high front vowels. In many treatments,
   both are considered a type of rounding, and are often called endolabial
   rounding (pursed, where the insides of the lips approach each other)
   and exolabial rounding (compressed, where the margins of the lips
   approach each other). However, some phoneticians do not believe that
   these are subsets of a single phenomenon of rounding, and prefer
   instead the three independent terms rounded, compressed, and spread
   (for unrounded).

Nasalization

   Nasalization refers to whether some of the air escapes through the
   nose. In nasal vowels, the velum is lowered, and some air travels
   through the nasal cavity as well as the mouth. An oral vowel is a vowel
   in which all air escapes through the mouth. French, Polish and
   Portuguese contrast nasal and oral vowels.

Phonation

   Voicing describes whether the vocal cords are vibrating during the
   articulation of a vowel. Most languages only have voiced vowels, but
   several Native American languages, such as Cheyenne and Totonac,
   contrast voiced and devoiced vowels. Vowels are devoiced in whispered
   speech. In Japanese and Quebec French, vowels that are between
   voiceless consonants are often devoiced.

   Modal voice, creaky voice, and breathy voice (murmured vowels) are
   phonation types that are used contrastively in some languages. Often,
   these co-occur with tone or stress distinctions; in the Mon language,
   vowels pronounced in the high tone are also produced with creaky voice.
   In cases like this, it can be unclear whether it is the tone, the
   voicing type, or the pairing of the two that is being used for phonemic
   contrast. This combination of phonetic cues (i.e. phonation, tone,
   stress) is known as register or register complex.

Tongue root retraction

   Advanced tongue root (ATR) is a feature common across much of Africa.
   The contrast between advanced and retracted tongue root resembles the
   tense/lax contrast acoustically, but they are articulated differently.
   ATR vowels involve noticeable tension in the vocal tract.

Secondary narrowings in the vocal tract

   Pharyngealized vowels occur in some languages; Sedang uses this
   contrast, as do the Tungusic languages. Pharyngealisation is similar in
   articulation to retracted tongue root, but is acoustically distinct.

   A stronger degree of pharyngealisation occurs in the Northeast
   Caucasian languages and the Khoisan languages. These might be called
   epiglottalized, since the primary constriction is at the tip of the
   epiglottis.

   The greatest degree of pharyngealisation is found in the strident
   vowels of the Khoisan languages, where the larynx is raised, and the
   pharynx constricted, so that either the epiglottis or the arytenoid
   cartilages vibrate instead of the vocal chords.

   Note that the terms pharyngealized, epiglottalized, strident, and
   sphincteric are sometimes used interchangeably.

Rhotic vowels

   Rhotic vowels are the "R-colored vowels" of English and a few other
   languages.

Tenseness/checked vowels vs. free vowels

   Tenseness is used to describe the opposition of tense vowels as in
   leap, suit vs. lax vowels as in lip, soot. This opposition has
   traditionally been thought to be a result of greater muscular tension,
   though phonetic experiments have repeatedly failed to show this.

   Unlike the other features of vowel quality, tenseness is only
   applicable to the few languages that have this opposition (mainly
   Germanic languages, e.g. English), whereas the vowels of the other
   languages (e.g. Spanish) cannot be described with respect to tenseness
   in any meaningful way. In discourse about the English language, "tense
   and lax" are often used interchangeably with "long and short",
   respectively, because the features are concomitant in the common
   varieties of English. This cannot be applied to all English dialects or
   other languages.

   In most Germanic languages, lax vowels can only occur in closed
   syllables. Therefore, they are also known as checked vowels, whereas
   the tense vowels are called free vowels since they can occur in any
   kind of syllable.

Acoustics

          Related article: Phonetics.

   Spectrogram of vowels [i, u, ɑ]. [ɑ] is a low vowel, so its F1 value is
   higher than that of [i] and [u], which are high vowels. [i] is a front
   vowel, so its F2 is substantially higher than that of [u] and [ɑ],
   which are back vowels.
   Enlarge
   Spectrogram of vowels [i, u, ɑ]. [ɑ] is a low vowel, so its F1 value is
   higher than that of [i] and [u], which are high vowels. [i] is a front
   vowel, so its F2 is substantially higher than that of [u] and [ɑ],
   which are back vowels.

   The acoustics of vowels are fairly well understood. The different vowel
   qualities are realized in acoustic analyses of vowels by the relative
   values of the formants, acoustic resonances of the vocal tract which
   show up as dark bands on a spectrogram. The vocal tract acts as a
   resonant cavity, and the position of the jaw, lips, and tongue affect
   the parameters of the resonant cavity, resulting in different formant
   values. The acoustics of vowels can be visualized using spectrograms,
   which display the acoustic energy at each frequency, and how this
   changes with time.

   The first formant, abbreviated "F1", corresponds to vowel openness
   (vowel height). Open vowels have high F1 frequencies while close vowels
   have low F1 frequencies, as can be seen at right: The [i] and [u] have
   similar low first formants, whereas [ɑ] has a higher formant.

   The second formant, F2, corresponds to vowel frontness. Back vowels
   have low F2 frequencies while front vowels have high F2 frequencies.
   This is very clear at right, where the front vowel [i] has a much
   higher F2 frequency than the other two vowels. However, in open vowels
   the high F1 frequency forces a rise in the F2 frequency as well, so a
   better measure of frontness is the difference between the first and
   second formants. For this reason, vowels are usually plotted as F1 vs.
   F2 – F1. (This dimension is usually called 'backness' rather than
   'frontness', but the term 'backness' can be counterintuitive when
   discussing formants.)

   R-colored vowels are characterized by lowered F3 values.

   Rounding is generally realized by a complex relationship between F2 and
   F3 that tends to reinforce vowel backness. One effect of this is that
   back vowels are most commonly rounded while front vowels are most
   commonly unrounded; another is that rounded vowels tend to plot to the
   right of unrounded vowels in vowel charts. That is, there is a reason
   for plotting vowel pairs the way they are.

Prosody and intonation

   The features of vowel prosody are often described independently from
   vowel quality. In non-linear phonetics, they are located on parallel
   layers. The features of vowel prosody are usually considered not to
   apply to the vowel itself, but to the syllable, as some languages do
   not contrast vowel length separately from syllable length.

   Intonation encompasses the changes in pitch, intensity, and speed of an
   utterance over time. In tonal languages, in most cases the tone of a
   syllable is carried by the vowel, meaning that the relative pitch or
   the pitch contour that marks the tone is superimposed on the vowel. If
   a syllable has a high tone, for example, the pitch of the vowel will be
   high. If the syllable has a falling tone, then the pitch of the vowel
   will fall from high to low over the course of uttering the vowel.

   Length or quantity refers to the abstracted duration of the vowel. In
   some analyses this feature is described as a feature of the vowel
   quality, not of the prosody. Japanese, Finnish, Hungarian, Arabic and
   Latin have a two-way phonemic contrast between short and long vowels.
   The Mixe language has a three-way contrast among short, half-long, and
   long vowels, and this has been reported for a few other languages,
   though not always as a phonemic distinction. Long vowels are written in
   the IPA with a triangular colon, which has two equilateral triangles
   pointing at each other in place of dots ([iː]). The IPA symbol for
   half-long vowels is the top half of this ([iˑ]). Longer vowels are
   sometimes claimed, but these are always divided between two syllables.

   It should be noted that the length of the vowel is a grammatical
   abstraction, and there may be more phonologically distinctive lengths.
   For example, in Finnish, there are five different physical lengths,
   because stress is marked with length on both grammatically long and
   short vowels. However, Finnish stress is not lexical and is always on
   the first two moras, thus this variation serves to separate words from
   each other.

   In non-tonal languages, like English, intonation encompasses lexical
   stress. A stressed syllable will typically be pronounced with a higher
   pitch, intensity, and length than unstressed syllables. For example in
   the word intensity, the vowel represented by the letter 'e' is
   stressed, so it is longer and pronounced with a higher pitch and
   intensity than the other vowels.

Pronunciation in English

   Close Unrounded vowels: Close Rounded vowels:
   The Front [i] is pronounced as in beet ( RP, GA, AuE, NZE). Front [y]:
   does not occur in English.
   Central [ɨ]: roses (in some dialects). Central [ʉ]: boot (AuE, NZE).
   Back [ɯ] does not occur in English. Back [u]: boot ( RP, GA).
   Near-close Unrounded vowels: Near-close Rounded vowels:
   Near-front [ɪ]: bit ( RP, GA, AuE, NZE). Near-front [ʏ] does not occur
   in English.
   Near-back [ʊ]: hook.
   Schwa vowel:
   Schwa [ə]: about, synonym, Rosa.
   Close-mid Unrounded vowels: Close-mid Rounded vowels:
   Front [e]: play ( RP), bait (CaE), bed (AuE, NZE). Front [ø] does not
   occur in English.
   Central [ɘ]: nut ( SAE). Central [ɵ] does not occur in English.
   Back [ɤ]: hope ( YE). Back [o]: ball (AuE, NZE), boat (CaE).
   Open-mid Unrounded vowels: Open-mid Rounded vowels:
   Front [ɛ]: bed ( GA), fat (AuE, NZE). Front [œ] does not occur in
   English.
   Central [ɜ]: fur ( RP, AuE, NZE), perfect ( GA). Central [ɞ] does not
   occur in English.
   Back [ʌ]: nut ( GA, east AmE, SE, BA). Back [ɔ]: ball ( RP), hot (AuE,
   NZE).
   Near-open Unrounded vowels: Near-open Rounded vowels:
   Front [æ]: fat ( RP, GA, AuE, NZE).
   Central [ɐ]: cut ( RP, AE).
   Open Unrounded vowels: Open Rounded vowels:
   Front [a]: lie, how ( GA, RP), cut, cart (AuE, NZE),

   bat (CaE, NE, SE), stock ( NCVS), star, father ( BA).
   Front [ɶ] does not occur in English.
   Back [ɑ]: spa ( RP, GA), ball (CaE), buy (AuE, NZE). Back [ɒ]: hot (
   RP).

Monophthongs, diphthongs, triphthongs

   A vowel sound whose quality doesn't change over the duration of the
   vowel is called a monophthong. Monophthongs are sometimes called "pure"
   or "stable" vowels. A vowel sound that glides from one quality to
   another is called a diphthong, and a vowel sound that glides between
   three qualities is a triphthong.

   All languages have monophthongs and many languages have diphthongs, but
   triphthongs or vowel sounds with even more target qualities are
   relatively rare cross-linguistically. English has all three types: the
   vowel sound in hit is a monophthong [ɪ], the vowel sound in boy is in
   most dialects a diphthong [ɔɪ], and the vowel sounds of, flower (BrE
   [aʊə] AmE [aʊɚ]) form a triphthong (disyllabic in the latter cases),
   although the particular qualities vary by dialect.

   The longest sensible word with most consecutive vowels is Finnish
   riiuuyöaieuutinen (courting night intention news [certainly yellow
   press stuff!]), syllabicated rii-uu-yö-ai-e-uu-ti-nen.

   In phonology, diphthongs and triphthongs are distinguished from
   sequences of monophthongs by whether the vowel sound may be analyzed
   into different phonemes or not. For example, the vowel sounds in a
   two-syllable pronunciation of the word flower (BrE [flaʊə] AmE [flaʊɚ])
   phonetically form a disyllabic triphthong, but are phonologically a
   sequence of a diphthong (represented by the letters <ow>) and a
   monophthong (represented by the letters <er>). Some linguists use the
   terms diphthong and triphthong only in this phonemic sense.

Vowels in languages

   The semantic significance of vowels varies widely depending on the
   language. In some languages, particularly Semitic languages, vowels
   mostly serve to denote inflections. This is similar to English man vs.
   men. In fact, the alphabets used to write the Semitic languages, such
   as the Hebrew alphabet and the Arabic alphabet, do not ordinarily mark
   all the vowels. These alphabets are technically called abjads. Although
   it is possible to construct simple English sentences that can be
   understood without written vowels (cn y rd ths?), extended passages of
   English lacking written vowels are difficult if not impossible to
   completely understand (consider dd, which could be any of add, aided,
   dad, dada, dead, deed, did, died, dodo, dud, dude, eddie, iodide, or
   odd).

   In most languages, vowels are an unchangeable part of the words, as in
   English man vs. moon which are not different inflectional forms of the
   same word, but different words. Vowels are especially important to the
   structures of words in languages that have very few consonants (like
   Polynesian languages such as Maori and Hawaiian), and in languages
   whose inventories of vowels are larger than their inventories of
   consonants.

Vowel systems

   Most languages have 3–7 vowels, the following 5-vowel system being the
   most common:
   /i/ /u/
   /e/ /o/
    /a/

   This configuration is often thought to be particularly stable because
   it makes efficient use of the vowel space, in that slight variations in
   one vowel are not confused for another vowel. Spanish and Modern Greek,
   for example, have this vowel system; Latin had a similar system with
   the addition of (unwritten) vowel length; it is for this reason that
   the Latin alphabet has five vowel letters.

   All known languages have at least two vowels: Abxaz, Ubykh, Margi,
   Eastern Arrernte, and perhaps some of the Ndu languages contrast only
   two vowels: /a/ and /ɨ/ in the case of Margi, and /a/ and /ə/ for the
   others, with significant allophony. There have been proposals to reduce
   the three-vowel inventory of Kabardian to two, one, or even zero vowels
   (in which case all phonetic vowels would be epenthetic), but most
   linguists do not believe such analyses are workable.

   Three-vowel systems have been noted in a large number of languages.
   These include,
     * /a, i, u/ Quechua, many Australian languages, Standard Arabic),
     * /i, a, o/ ( Pirahã),
     * /ɨ, ə, aː/ ( Kabardian),
     * /i, e, a/ ( Wichita).

   A fair number of Native American languages, such as Nahuatl and Navajo,
   have vowel systems that lack /u/, but there is no known language that
   lacks some form of a. At the other end of the spectrum, languages with
   more than twelve vowels are uncommon, although some widely-spoken
   languages have large vowel inventories, particularly Germanic
   languages. For example, English has 14–20 vowels (including diphthongs)
   depending on dialect, and Swedish has 17 distinct vowel qualities in
   the height-backness-roundedness spectrum, although these also involve a
   length contrast, and the long vowels have diphthongized allophones.
   Some Norwegian dialects (in the municipalities Tynset and Alvdal in
   Hedmark county) have 14 standard vowels (and in addition comes length
   contrast and diphtongs, which give a total of 28 distinct vowel
   qualities). The oldest form of Norse (before 1200) had nine vowels (a,
   e, i, o, u, y, æ, ø and ǫ), and all these could either be short orals,
   long orals or long nasals. This gave a total of 27 distinct monophtongs
   - and in addition was three diphtongs (au, ei and ey). French has 16
   vowel qualities, including nasals, and the previously-mentioned Sedang
   has 24 distinct monophthongs, which it achieves by contrasting
   phonation on seven vowel qualities. Ju/’hoan uses phonation and
   nasalization with five vowel qualities to achieve approximately 40
   vowels, most of which may in addition occur both long and short.

Written vowels

   The name "Vowel" is often used for the symbols used for representing
   vowel sounds in a language's writing system, particularly if the
   language uses an alphabet. In the Latin alphabet, the vowel letters are
   A, E, I, O, U, and Y; in addition, extensions of the Latin alphabet
   have independent vowel letters such as Ä, Ö, Ü, Å, Æ, and Ø. The
   phonetic values vary by language, and some languages use I and Y for
   the consonant [j], e.g. initial I in Romanian and initial Y in English.
   Some languages using the Latin alphabet may use other letters to
   represent vowel sounds: for example, in Welsh, the letter W stands for
   [u] or [ʊ], while in Creek the letter V stands for [ə].

   There is not necessarily a direct one-to-one correspondence between the
   vowel sounds of a language and the vowel letters. Many languages that
   use a form of the Latin alphabet have more vowel sounds than can be
   represented by the standard set of five vowel letters. In the case of
   English, the five primary vowel letters can represent a variety of
   vowel sounds.

   Notice "conventional" vowel letters functioning in actual vocabulary,
   as they take their role in representing unique sounds in each word: "a"
   ask, broad, along, any, apex, aisle, war, beauty, aeon, all, learn; "e"
   have, pretty, gone, the, egg, where, height, beau, sleuth, he,
   sergeant, house, noise, her; "i" plain, in, friend, nail, I, suit, ski,
   oil, shirt; "o" women, log, ton, leopard, go, who, people, book, cow,
   boy, worm; "u" laugh, busy, cough, bug, busy, guy, your, tube, auto,
   put, out, fur; "y" gym, says, day, by, any, boy, syrup, yellow. For
   this reason, new pedagogy requires "spelling-out-sounds" instead of
   "sounding-out-letters". More research on this topic is posted at
   WordsAhead.org.

   Other languages cope with the limitation in the number of Latin vowel
   letters in similar ways. Many languages, like English, make extensive
   use of combinations of vowel letters to represent various sounds. Other
   languages use vowel letters with modifications, e.g. Ä in Finnish, or
   add diacritical marks to vowels, such as accents or umlauts, to
   represent the variety of possible vowel sounds. Some languages have
   also constructed additional vowel letters by modifying the standard
   Latin vowels in other ways, such as æ or ø that are found in some of
   the Scandinavian languages. The International Phonetic Alphabet has a
   set of 28 symbols to represent the range of basic vowel qualities, and
   a further set of diacritics to denote variations from the basic vowel.

Written vowels in writing systems

     * Arabic: long vowels: ا و ي; short vowels: ِ ُ َ
     * Armenian: ա ե է ը ի ո օ ու իւ էօ
     * Bulgarian: non- iotated ('hard'): А О У Ъ; iotated ('soft'): Я Ю И
       Е
     * Czech: a e i o u y, long with an acute á é í ó ú ý or a ring ů,
       softening ě
     * Danish, Norwegian, and Swedish: back ('hard'): a o u å; front
       ('soft'): e i y æ/ä ø/ö
     * Devanagari: Independent vowels: अ आ इ ई उ ऊ ए ऐ ओ औ; Dependent
       vowels: ा ि ी ु ू े ै ो ौ
     * Estonian and Võro: a e i o u ü ä ö õ (y); half-long and over-long
       vowels doubled
     * Finnish: back: a o u; neutral: i e; front: ä ö y; long vowels
       doubled (aamu, uuma, etc.)
     * Guaraní: oral: a e i o u y; nasal: ã ẽ ĩ õ ũ ỹ
     * German: a ä e i o ö u ü
     * Korean: ㅏ ㅐ ㅑ ㅒ ㅓ ㅔ ㅕ ㅖ ㅗ ㅘ ㅙ ㅚ ㅛ ㅜ ㅝ ㅞ ㅟ ㅠ ㅡ ㅢ ㅣ
     * Hebrew: ֱ ֲ ֳ ְ ֻ ֹ ִ ֵ ֶ ַ ָ (see Niqqud)
     * Japanese: normal: あいうえお; grammatical: へを
     * Latin: a e i o u y
     * Polish: a ą e ę i o ó u y
     * Russian: non- iotated ('hard'): А О У Ы Э; iotated ('soft'): Я Ё Ю
       И Е
     * Skolt Sami: u o õ å a, i e â ä (normal); long vowels doubled
       (lääij, nââ'ǩǩted, etc.).
     * Turkish: a ı o u ('thick'), e i ö ü ('thin')

     * Vietnamese: a ă â e ê i o ô ơ u ư y, plus tonal marks (e.g. ầ, ứ,
       ...).

   Retrieved from " http://en.wikipedia.org/wiki/Vowel"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
   of authors and sources) and is available under the GNU Free
   Documentation License. See also our Disclaimer.
