3. 2.3 The long vowels i : and u : are produced comparatively for a longer duration than their short counterparts1 1, I are nodoubt approximants similar to the nucleus occurring either as coda or as onset. According to the definition given for the quantity, both long vowels and the sequence of vowel and approximant are to be treated as quantity difference when compared to the shorter or single ones. But in the sequence type a gradual change of quality is involved since the vocal configuration is gradually reduced to a frictionless release position. The long vowel as a peak behaves like a single unit both in form as well as in function. The vowel sequence with approximation behaves partly as peak and partly as coda or onset like a complex unit of having two or three segments. Instrumental analysis 3.1 Vowels. The following results are obtained when the words / i : /, / imay /, / i : yam /, / iyyam /, / u : may /, / umay /, / u : vay /, and / uvvay / are analySed. 3.1.1 Since u is labial sound palatographic study will not supply any information.” The word palatograms of i set of words are analysed. In all the cases the area of contact is the same except for / i : / and / i : yam /. Evidences for more clear and tense contact is noticed by the strong and complete wiping for the sequence of the vowel and homoorganic approximants. This shows that the segments have the same contact area but they differ in the mode of CO in tact. 3.1.2 The electro kymograms confirm that they are having the same duration. For / i : / though it is long there is no articulatory change. But for / i : y / or / Iy / there is articulatory change. 262
