Dinka Chari-Nile languages diphthong [Grk díphthongos ‘with two sounds’]

Vowel in the articulation of which the articulators move enough so that two separate phonological phases can be distinguished, e.g. [ay], [aυ] in high, how. According to different theoretical criteria, a diphthong can be considered a single (‘unit’) phoneme or a combination of two phonemes. The terms ‘rising’ and ‘falling’ are used to describe diphthongs in two different ways. (a) If the first phase is more open ( closed vs open) than the second, it is a rising diphthong, as in the examples above. If the first phase is more closed, it is falling, e.g. [oa] in Fr. bois ‘woods.’ (b) In a different terminology, a diphthong is said to be rising if the first element carries less stress1 than the second, as in Span. país ‘country’; it is falling if the first element carries greater stress, as in the English examples above. There is much debate about whether diphthongs in English consist of two vowels, or of one vowel and one glide. Numerous orthographic conventions prevail, e.g. [aυ] [au], [āυw]. ( also diaeresis, syllable)

References

phonetics

Sound change by which simple (long) vowels turn into variable vowels (diphthongs), due to a shift in articulation or to phonological or phonotactic pressures ( phonology), e.g. in the Great Vowel Shift OE īs [i:s]>Mod. Eng. ice [ays], OE hūs [hu:s] Mod. Eng. house [haυs]. ( also push chain vs drag chain)

References

Andersen, H. 1972. Diphthongization. Lg. 48. 11-50. Hayes, B. 1990. Dipthongization and coindexing. Phonology 7. 31-71. Rauch, I. 1967. The Old High German diphthongization: a description of a phonemic change. The

Hague.