Quality of American English front vowels before /r/

The vowels /i/ and /I/ are not contrastive before /r/ in American English, and the phonetics literature is equivocal about which symbol to use for the nucleus in words such as beer. Similarly /e/ and /ε/ are not contrastive before /r/, and the literature contains varied references to one or the other in words such as bear. The purpose of this study was to investigate these vowels by acoustic measurements, discriminant analyses, and listening tests. Eleven men and ten women residing in southern Michigan recorded /r/-final monosyllables (beer, bear, hear, hair), as well as words containing /i, I e, ε with other finals, such as beet, bit, bait, bet. Acoustic measurements included the first three formants at steady state. The high front vowel in /r/-final syllables (beer, hear) showed formant values intermediate between /i/ and /I/, but closer to /i/, and the mid front vowel (in bear and hair) was intermediate between /e/ and /ε/, but closer to /e/. Discriminant analysis using the first three formants and listening tests using 60 ms vowel excerpts yielded results consistent with the idea that the pre-/r/ vowels are acoustically intermediate between their tense and lax neighbors but resemble /i/ and /e/ more closely than /I/ and /ε/.