There have been various studies on dipthongs during the past four decades or so, but the interpretations and definitions of dipthongs do not always agree. Some hold a dipthong is a blend of two perceptually different vowels within one and the same syllable; others hold it is a sequence of vowel and semi-vowel; while still others hold it is a vocalic syllable nucleus containing two target positions.
The question then, is a dipthong really a pair of monophthongs, end to end? Is the perceived dipthong different from the perception of a pair of vowels? With the help of some attributes gathered from the results of a spectrographic study of the Maithili dipthongs, the author attempts to find some possible answers to this question.