Evidence for the distinction between "consonantal-/r/" and "vocalic-/r/" in American English.

We examine the distinction between "consonantal-r" and "vocalic-r" in American English, terms encountered in the speech pathology literature but rarely in phonetic studies. We review evidence from phonetics, phonology and therapy, and describe our own study which measured percentage rhoticity in pre- and post-vocalic /r/. We suggest that the evidence supports a view that there is no more variation between pre-vocalic and post-vocalic /r/ than found in many other consonants. We also evaluate the different transcription traditions for post-vocalic /r/ in American English (as a consonant or a vowel), and describe a preliminary study demonstrating that these transcriptions are not equivalent, and denote different realisations.