Compensatory articulation in American English nasalized vowels

In acoustic studies of vowel nasalization, it is sometimes assumed that the primary articulatory difference between an oral vowel and a nasal vowel is the coupling of the nasal cavity to the rest of the vocal tract. Acoustic modulations observed in nasal vowels are customarily attributed to the presence of additional poles affiliated with the naso-pharyngeal tract and zeros affiliated with the nasal cavity. We test the hypothesis that oral configuration may also change during nasalized vowels, either enhancing or compensating for the acoustic modulations associated with nasality. We analyze tongue position, nasal airflow, and acoustic data to determine whether American English /i/ and /a/ manifest different oral configurations when they are nasalized, i.e. when they are followed by nasal consonants. We find that tongue position is higher during nasalized [ĩ] than it is during oral [i] but do not find any effect for nasalized [ã]. We argue that speakers of American English raise the tongue body during nasalized [ĩ] in order to counteract the perceived F1-raising (centralization) associated with high vowel nasalization.