Natasha Warner's current and recent research

• Production and processing of reduced speech. The main focus of the Douglass Phonetics Lab at this point is reduced speech, examining both acoustics of reduced speech and perception and psycholinguistic processing of it. We have been working on several sub-projects in this area. Normal casual daily-life speech is filled with rampant reduction and variability (sounds and syllables disappearing, voiceless stops appearing as voiced approximants, vowels appearing as voiceless fricatives, etc.), and yet the vast majority of speech research examines careful, non-reduced speech, often words produced in isolation. This is not the type of speech most of us process during most of every day. We are studying reduced speech through a large acoustic study of American English flaps, analyzing for example how often flaps surface as approximants rather than true flaps, how much variability within and among speakers there is in reduction, how much reduction is explained by speech style vs. speech rate vs. word frequency, etc. We are also studying processing of reduced speech, both reduced flaps and more general reduction, through lexical decision and cross-modal identity priming experiments (Ben Tucker). Another project on processing of Japanese devoiced vowels in a fast speech environment (Naomi Ogasawara) also addresses processing of reduction. Collaborators: Ben Tucker (soon to be at U. Alberta, Edmonton) and Naomi Ogasawara (soon to be at Taiwan Normal University).
• Revitalization of the Mutsun language. Mutsun was spoken near San Juan Bautista, California, until approximately 1930, when the last fluent speaker died. The Mutsun community has been working on revitalization since 1996. Natasha Warner and a group at the University of Arizona participate by compiling a dictionary from published sources and field notes, and by assisting in the development of language teaching materials. NEH Preservation and Access funding (2005-2007) and a Woodrow Wilson Foundation Public Scholarship Grant (2003) have allowed us to enter all of the existing documentation about Mutsun into databases and analyze it, leading to a much clearer understanding of the language for revitalization purposes. Collaborators: Quirina Luna (Amah Mutsun tribe), Lynnika Butler (University of Arizona), Heather van Volkinburg (soon to be at Columbia University), and numerous student volunteers.
• The relationship of intonation and speech segmentation. This project investigates speech of several speech styles (e.g. read connected text, spontaneous conversation) in several languages to determine what features of intonational systems have the potential to serve as word boundary cues for listeners in their task of separating words out of connected speech. Psycholinguistic perceptual studies investigate whether listeners can indeed use these intonational cues to help them locate word boundaries. Collaborators: Takayuki Arai (Sophia University, Tokyo), Takashi Otake (Dokkyo University, Tokyo).
• Navajo spoken word recognition and phonetics. The spoken word recognition aspect of this project investigates how speakers of Navajo process verbs and nouns with either few or many morphemes, focussing especially on the role of the verbal morphology in recognition. The phonetics aspect of this project examines influences of the first and second language phonologies on phonoloical categories, where Navajo and English are the first and second languages, in fluent speakers, semi-fluent speakers, and novice learners of Navajo. Collaborators: Mary Willie (University of Arizona), Alina Twist (University of Arizona), James McQueen (Max Planck Institute, Nijmegen).
• Incomplete neutralization in Dutch. (Completed project) This project investigates the production and perception of neutralization of voicing in final position in Dutch, which appears to involve the maintenance of very small differences in duration (incomplete neutralization). This study also investigates the influence of orthography in creating such sub-phonemic differences. Collaborators: Allard Jongman (University of Kansas), Joan Sereno (University of Kansas), Rachel Kemps (University of Nijmegen).
• Phonology and speech segmentation in Korean. (Completed project) This project investigates listeners’ use of language-specific phonology in segmenting speech in Korean. Completed research has shown that segmentation is affected by phonotactic constraints, even though these phonotactic constraints are variable and are created by several interacting aspects of Korean phonology. Further research will investigate how Korean listeners’ interpretation of speech strings is affected by a particular phonological pattern which shows non-derived environment blocking. Collaborators: Jeesun Kim (University of Melbourne), Chris Davis (University of Melbourne), Anne Cutler (Max Planck Institute, Nijmegen).
• Stop epenthesis. (Completed project) This project investigates the production and perception of epenthetic stops between nasals and following obstruents, such as the optional [k] in “youngster.” The project focuses primarily on Dutch. This research has shown that listeners quite often interpret phonetically variable epenthetic stops as real tokens of the stop phoneme, and that listeners are influenced by phonotactic constraints of their language in doing so: they are less likely to report epenthetic stops when the epenthetic stops would violate phonotactic constraints of the language. Collaborator: Andrea Weber (University of Saarbrücken).
• Vowel epenthesis. (Completed project) This project uses articulatory data on the production of /l/ before epenthetic schwa in Dutch, and argues that the light/dark /l/ alternation in Dutch contradicts the assumption of Articulatory Phonology that gestures cannot be inserted in the process of speech production. Collaborators: Allard Jongman (University of Kansas), Anne Cutler (Max Planck Institute, Nijmegen), Doris Mücke (University of Cologne).
• Perception of gated Dutch diphones. (Completed project) This project provides a large database on how listeners’ perception of sounds changes over time as the acoustic signal unfolds. This information will be used as input to a model of spoken word recognition. Collaborators: Roel Smits (Max Planck Institute, Nijmegen), James McQueen (Max Planck Institute, Nijmegen), Anne Cutler (Max Planck Institute, Nijmegen).