In phonetics, vowel roundedness refers to the amount of rounding in the lips during the articulation of a vowel. It is labialization of a vowel, when a rounded vowel is pronounced, the lips form a circular opening, and unrounded vowels are pronounced with the lips relaxed. In most languages, front vowels tend to be unrounded, in the International Phonetic Alphabet vowel chart, rounded vowels are the ones that appear on the right in each pair of vowels. There are diacritics, U+0339 ̹ COMBINING RIGHT HALF RING BELOW and U+031C ̜ COMBINING LEFT HALF RING BELOW, to greater and lesser degrees of rounding. The more and less rounded diacritics are used with consonants to indicate degrees of labialization. There are two types of rounding and compression. In protruded rounding, the corners of the mouth are drawn together, in compressed rounding, the corners of the mouth are drawn together, but the lips are drawn together horizontally and do not protrude, with only their outer surface visible. That is, in protruded vowels the inner surfaces of the form the opening.
Catford observes that back and central rounded vowels, such as German /o/ and /u/, are typically protruded, whereas front rounded vowels such as German /ø/ and /y/ are typically compressed. Back or central compressed vowels and front protruded vowels are uncommon, there are no dedicated IPA diacritics to represent the distinction, but the superscript IPA letter ⟨◌ᵝ⟩ can be used for compression and ⟨◌ʷ⟩, ⟨◌ᶣ⟩ or ⟨◌̫⟩ for protrusion. Compressed vowels may be pronounced either with the corners of the mouth drawn in, by some definitions rounded, or with the spread and, by the same definitions. The distinction may be transcribed ⟨ɨᵝ ɯᵝ⟩ and ⟨ʉᵝ uᵝ⟩, the distinction between protruded and compressed holds for the semivowels and as well as labialization. In Akan, for example, the is compressed, as are labio-palatalized consonants as in Twi Twi and adwuma work, whereas, in Japanese, the /w/ is compressed rather than protruded, paralleling the Japanese /u/. The distinction applies marginally to other consonants, some vowels transcribed with rounded IPA letters may not be rounded at all.
An example is /ɒ/, which in English has very little if any rounding of the lips, the throaty sound of English /ɒ/ is instead accomplished with sulcalization, a furrowing of the back of the tongue found in non-rhotic /ɜː/. It is possible to mimic the effect of rounded vowels by narrowing the cheeks, so-called cheek rounding. The technique is used by ventriloquists to mask the visible rounding of back vowels like and it is not clear if it is used by languages with rounded vowels that do not use visible rounding. Protruded rounding is the equivalent of consonantal labialization
Front vowels are sometimes called bright vowels because they are perceived as sounding brighter than the back vowels. Near-front vowels are essentially a type of front vowels, no language is known to contrast front and near-front vowels based on frontness alone, rounded front vowels are typically centralized, that is, near-front in their articulation. This is one reason they are written to the right of unrounded front vowels in the IPA vowel chart, in articulation, front vowels contrast with raised vowels and retracted vowels. In this conception, front vowels are a broader category than those listed in the IPA chart, raised or retracted vowels may be fronted by certain consonants, such as palatals and in some languages pharyngeals. For example, /a/ may be fronted to next to /j/ or /ħ/ and this change can be allophonic variation, or it can have become phonemic. English follows the French pattern, but without as much regularity, for native or early borrowed words affected by palatalization, English has generally altered the spelling after the pronunciation Back vowel List of phonetics topics
International Phonetic Alphabet
The International Phonetic Alphabet is an alphabetic system of phonetic notation based primarily on the Latin alphabet. It was devised by the International Phonetic Association as a representation of the sounds of spoken language. The IPA is used by lexicographers, foreign students and teachers, speech-language pathologists, actors, constructed language creators. The IPA is designed to represent only those qualities of speech that are part of language, phonemes, intonation. IPA symbols are composed of one or more elements of two types and diacritics. For example, the sound of the English letter ⟨t⟩ may be transcribed in IPA with a letter, or with a letter plus diacritics. Often, slashes are used to signal broad or phonemic transcription, thus, /t/ is less specific than, occasionally letters or diacritics are added, removed, or modified by the International Phonetic Association. As of the most recent change in 2005, there are 107 letters,52 diacritics and these are shown in the current IPA chart, posted below in this article and at the website of the IPA.
In 1886, a group of French and British language teachers, led by the French linguist Paul Passy, for example, the sound was originally represented with the letter ⟨c⟩ in English, but with the digraph ⟨ch⟩ in French. However, in 1888, the alphabet was revised so as to be uniform across languages, the idea of making the IPA was first suggested by Otto Jespersen in a letter to Paul Passy. It was developed by Alexander John Ellis, Henry Sweet, Daniel Jones, since its creation, the IPA has undergone a number of revisions. After major revisions and expansions in 1900 and 1932, the IPA remained unchanged until the International Phonetic Association Kiel Convention in 1989, a minor revision took place in 1993 with the addition of four letters for mid central vowels and the removal of letters for voiceless implosives. The alphabet was last revised in May 2005 with the addition of a letter for a labiodental flap, apart from the addition and removal of symbols, changes to the IPA have consisted largely in renaming symbols and categories and in modifying typefaces.
Extensions to the International Phonetic Alphabet for speech pathology were created in 1990, the general principle of the IPA is to provide one letter for each distinctive sound, although this practice is not followed if the sound itself is complex. There are no letters that have context-dependent sound values, as do hard, the IPA does not usually have separate letters for two sounds if no known language makes a distinction between them, a property known as selectiveness. These are organized into a chart, the chart displayed here is the chart as posted at the website of the IPA. The letters chosen for the IPA are meant to harmonize with the Latin alphabet, for this reason, most letters are either Latin or Greek, or modifications thereof. Some letters are neither, for example, the letter denoting the glottal stop, ⟨ʔ⟩, has the form of a question mark