The vowel system in Juralic was very simple, as follows:

SHORT:   A   E   I   O   U            LONG:   A:   E:   I:   O:   U:         HALF VOWELS:   W   Y

As far as we know from the sources, the vowels  would have been pronounced roughly as in "modern" languages such as Latin or Italian. "W" was presumably similar to the same letter in English. "Y" was sounded like modern English "Y" in, for example, "yacht".

The table below shows original vowels in Juralic, and how they developed to Atlanchalcric  (between -900 and -500), and hence to Imperial Atlantean (300-600), Standard Chalcran (-250 onwards), Imperial Helvran (-200 - 500) and Early Yalland (-200 - 500). North Atlantean (-200 - c350) and Atlantid (-200 - c400) forms are also shown, where they vary from Early and Imperial Atlantean. Atlantean, Helvran and Yalland also continued on and changed somewhat into "late" forms after 500. Chalcran died out by 600. Note that vowels may be long (: written after them) or short. They may also vary in later forms of some of Helvran, because of ablaut, if there is an "i" in the following syllable. Also, "e", "o" and "u" before nasals or liquids in Juralic may change in some of its descendants. In Chalcran and Yalland, their development depended upon whether the syllable they ended up in was stressed or unstressed. Where nothing is written in a space, it means that there has been no change from the earlier stage of the language. 

Below the vowel-changes, are examples of words indicating these changes (written in italics).