Low Vowels

Low vowels (or open vowels) are vowels that are pronounced with the jaw dropped as low as it can be and with the tongue flattened. Low vowels are the most sonorous sounds humans can pronounce.

Low Vowels in Orish
In Orish, the sound of the letter A is the only low vowel. There is a high risk that if there were more than one open vowel people would not manage to distinguish them (hear the difference between them or be able to pronounce them correctly), and the two low vowels would merge and it would be difficult to know how to spell words with them. So there is only one low vowel in Orish to prevent that.