Second International Conference on Spoken Language Processing (ICSLP'92)
Banff, Alberta, Canada
This paper investigates the context-dependent variability demonstrated by function words. Thirty different monosyllabic function words were selected from a twenty-minute text reading by one speaker. Traces of Fl, F2 and F3 were obtained for the vowels in multiple occurrences of these words, covering as many phonemic, grammatical, and positional conditions as were available. Formant behavior was examined in terms of various factors, and results were contrasted with previous findings for stressed vowels from content words. Fl's variability is fairly predictable from vowel identity; F3 varies within a small range and is relatively high; the pattern for F2 is similar to that of corresponding stressed vowels, though its range is extremely wide (particularly for /i/ vowels). In phrase-initial position, especially when the function word begins with a vowel, Fl and F2 frequencies approach canonical values at vowel onset. A centralizing effect is seen with F2 in phrase-medial position, and with both Fl and F2 in phrase-final position. The effect of a consonant environment on F2 depends on a complex interplay of factors: the consonant's identity, its position (preceding or following) relative to the vowel, whether a phrase boundary intervenes, and the syllabic make-up of the function word.
Bibliographic reference. Umeda, Noriko (1992): "Formant frequencies of vowels in English function words", In ICSLP-1992, 947-950.