American English Rhotic Rhymes: Phonemic rhotacized schwa or underlying /V+ɹ/?

This study examines the possibility that American English has developed a rhotic vowel phoneme /ɚ~ɝ/ distinct from consonantal /ɹ/. This claim is based on the perceptual and (putative) acoustic stability of realizations of so-called syllabic /ɹ/ as a rhotacized schwa [ɚ] (or its stressed counterpart [ɝ]) in words like ‘bird’, ‘father’, ‘survive’, etc. Among potentially syllabic sonorants (i.e. /l m n/), /ɹ/ stands out as an approximant, patterning with /j w/ as a vocoid which acts as a consonant. Syllabic /ɹ/ is also found in both stressed and unstressed position, at odds with the restriction of syllabic /l m n/ to unstressed syllables. Thirteen adult native speakers of American English were recorded reading tokens of prevocalic /ɹ/, postvocalic /ɹ/, stressed syllabic /ɹ/, unstressed syllabic /ɹ/, and syllabic /l/. The ‘stability’ of syllabic /ɹ/ was investigated using the achievement of a stable close proximity between the second and third formants (as opposed to a decline in raw F3 value) to identify achievement of rhoticity and to measure its duration relative to the /Vɹ/ sequence as a whole. A majority of subjects exhibited acoustically distinct vowel and rhotic portions even in perceptually stable tokens of syllabic /ɹ/. This, along with evidence from backwards talkers and issues of syllabification in word-medial position suggest that an analysis of /V+ɹ/ with a strong tendency to surface as a stable rhotacized schwa is more appropriate than attributing underlying /ɚ~ɝ/ to the surface phone. This conclusion is discussed with particular reference to the potential effect of individual variation in /ɹ/ articulation strategy on discreteness of coarticulation between schwa and an adjacent rhotic.