Further, the tongue positions are described in relationship to the positions assumed in the cardinal vowels.
The cardinal vowels represent a set of evenly spaced reference points on a vowel chart, such as the one in Figure 1, in the usual quadrilateral shape.
13) The concept of the cardinal vowels actually demonstrates this reality.
14 However, since the cardinal vowels are essentially guide posts for identifying, for example, a variety of sounds that fall within the framework for the symbol [i], this phenomenon makes perfect sense, supporting the notion that novel sounds in L2 are less likely to provide a context for transfer or interference from the L1 phonological system.
Identifying or placing the vowels of L1 and L2 in relation to the cardinal vowels on a chart provides a visual as well as auditory and articulatory context for exploring the similarities and differences between and among the vowels in L1 and L2 languages, allowing the learner to both see and hear the different sound values in the two languages.
For example, in the discussion of the cardinal vowels, it was noted that the cardinal vowel [i] actually represents a range of sounds that are high front sounds.