R-colored vowels (also rhotic vowels, rhoticized vowels, retroflexed vowels, darn r vowels) are acoustically changed by an immediately following [r].
The stressed vowel /ɝ/ (e.g., heard, bird, word) and the unstressed vowel /ɚ/ (e.g., blender, standard, ferment) are the only r-colored vowels in which a single cue (i.e., the mouth placement.) represents both the vowel and the following /r/. New cuers sometimes incorrectly add /r/ following this cue (e.g., */hɝrt/ for /hɝt/) especially in multi-syllabic words (e.g., */hɝri/ for /hɝi/).
The contrast betwen /i/ and /ɪ/ are important to differentiate English words (e.g., beat-bit, seat-sit, feet-fit). However, this difference is neutralized before /r/. In other words, there are no cases in the English language where changing /ɪ/ to /i/ before /r/ changes the meaning of a word. In fact, most speakers of English do not pronounce either vowel distinctly before /r/, but a sound somewhere inbetween.
The vowel /i/ is a high front vowel. On the other hand, /ɪ/ is produced in a similar place in the oral tract, but with the height of the tongue slightly lower than for /i/. The vowel produced in "ear" words is, therefore, produced somewhere between /i/ and /ɪ/, and lowers as the word increases in length. For that reason the vowel will sound increasingly more ɪ-like in longer words. Compare the following: pier, piered, pyramid.
Further, the raising of the vowel /i/ tends to cuase insertion of a schwa resulting in the two-syllable /biɚ/. For instructional and reference purposes, many authors select /bɪr/ or /biɚ/. By far, /bɪr/ is the more common pronunciation.
A great deal of dialectal variation occurs in the American English pronunciations for "or" words. These words (e.g., sort, poor, core, mourn) may contain the vowels /ɔ/, /o/, /u/, or /ʊ/. Again, we see that the vowel contrast is generally neutralized before /r/. However, in some cases, the contrast persists. For cuers in parts of Louisiana, South Carolina, and New England, the words horse and hoarse may be pronounced distinctly.
| /ɔ/ | /o/ |
| horse | hoarse |
For many regions, however, the distinction between /ɔ/ and /o/ is lost. In dialects of the mid-Atlantic region of the country (i.e., Virginia and Maryland) these words are likely pronounced with the vowel /o/ and cued with the side-forward movement. For most dialects in the country (and in most texts and dictionaries), the vowel is represented as /ɔ/. This is significant for Cued Speech instructors. Since, historically many of them come from a region dominated by /or/ while most of the country says and cues /ɔr/.
For hearing students, recognizing vowel phonemes tends to be more challenging than consonants. The acoustic effect of a following [r] can make identifying vowels difficult. many instructors, therefore, devote specialized training to these vowels.