Phonetic properties of vowels

In the description of vowels, tongue position plays a very important role. Accordingly, one of the important dimensions is related to the part of the tongue involved, and the other is related to the height of the tongue in the production of a specific vowel. According to the former criterion, English vowels can be classified as:

As for tongue height, we have the following groupings:

In some publications, a separation between ‘high-mid’ and ‘low-mid’ is given to separate /e/ and /o/ from /ε/ and /ɔ/.

If we put these two dimensions together, we obtain the vowel chart shown in figure 1.

Besides the tongue height and the tongue part involved, the vowels of English are also grouped according to the lip position. The binary split is between the rounded vowels (/u, ʊ, o, ɔ/), and the unrounded vowels (the remainder). All rounded vowels of English are back; in fact, we can make the following generalization: all non-low back vowels are rounded in English.