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Contact University of California, Berkeley 1203 Dwinelle Hall #2650 Berkeley, CA 94709, USA kataoka@berkeley.edu |
Brief Bio
I am a graduate student in the department of Linguistics at the University of California at Berkeley. My primary research interests include phonetics, psycholinguistics of speech perception, and sound change. I'm also interested in cross-linguistic variations in speech production and speech perception and phonetic categorization and learning within an exemplar-based memory. I also enjoy working for language revitalization programs. I did both of my Master's degree ('05) and Bachelor's degree ('03) at UCB. My dissertation committee members are: Professor Emeritus John Ohala, Professor Andrew Garrett, Professor Keith Johnson, and Professor Yoko Hasegawa.
Research
Current Research
Phonetic and Cognitive Bases of Sound Change (Ph. D dissertation)
I’m currently working on my dissertation (tentatively titled Phonetic and Cognitive Bases of Sound Change), the goal of which is to investigate physical, biological, and cognitive aspects that coexist in speech chain that uniquely define the output of speech perception: Most of the time listeners decode the phonological representations from acoustic information of the speech signals as they are meant by the speakers—a case of 'correct' perception, but from time to time the listeners construct the mental representations that differ from those of the speakers—a case of misperception, which may become a seed of sound change. This is an important area of inquiry both for the theory of sound change and for the theory of speech perception.
My approach to this goal is to study physiological and physical constraints that define the limit of possible speech sounds, the acoustic properties of the output speech sounds, and the way human listeners perceive them. I'm also exploring the effects of individual's knowledge about the fine phonetic details of speech sounds, which is largely shaped by the previous linguistic experience unique to each individual, both on their speech production and perception. The study consists of three main components. These are: phonologization, compensation for coarticulation, and variation in speech perception. Each of the component is briefly described in the followings:
>> Phonologization
In the course of sound change, there is a point where intrinsic and automatic pronunciation variation due to coarticulation becomes extrinsic and controlled pronunciation pattern (phonologization). Although phonologization is a useful concept in that it emphasizes the cognitive role in sound change, that a contextually predictable feature becomes dissociated from its contexts, diagnostic criteria for determining whether phonologization has or has not occurred when the context itself is still present have yet to be proposed. The question is how do we know whether a given pronunciation variation is a result of phonetic coarticulation or controlled context-specific articulation. Take, for example, a case of /u/-fronting in alveolar contexts in American English, e.g., ‘dude’ (/dud/) being pronounced as [dyd]. On the one hand, the alveolar environment would be expected to raise the 2nd formant of the vowel, thus leading to the vowel being fronted but is the extent of this fronting purely phonetic or could it have become phonological?
In order to investigate this question, I’m conducting a production experiment with native speakers of American English to investigate whether the magnitude of coarticulatory influence of the flanking consonants on the vowel reduces as the vowel’s duration increases. Results from a pilot study showed that the fronting of the vowel /u/ persists regardless of the manipulation of the vowel’s duration, suggesting that in American English /u/-fronting in alveolar context is phonologized. More data collection and analysis are currently under way.
>> Compensation for Coarticulation
In running speech, the phonetic form of consonants and vowels varies due to coarticulation (either phonologized or not) but the listener hears them as if there were no coarticulatory distortions on the segments. This phenomenon is often called by speech scientists as perceptual compensation for coarticulation or simply compensation for coarticulation (C for C). This is a type of context effect whereby auditory information about speech segments is "corrected " for irrelevant coarticulatory perturbation induced by surrounding sounds. This phenomenon is similar to constancy in visual perception, wherein visual information about object’s color, size, shape, etc. is “corrected” for irrelevant viewing conditions.
As a case study, I'm conducting a perceptual experiment investigatig how listeners compensate for coarticulatory fronting of high back vowel /u/ in alveolar contexts. In the pilot study, listeners were presented each of a series of ten vowels that vary perceptually between /i/ and /u/, a middle of which is an ambiguous vowel between /i/ and /u/. Broadly speaking, the results showed that the listeners heard the ambiguous vowel as [u] in alveolar context ('dVt') more often than in bilabial context ('bVp'), but the degree of such context effect (i.e. compensation) varied depending on other conditions such as presence or absence of precursor phrase and speech rate of the stimuli. Experiments are underway to further investigate how listeners employ various degree of compensation under different experimental conditions.
Some of the initial findings were reported in:
"A Study on Perceptual Compensation for /u/-fronting in American English." 2009 Annual Report, UC Berkeley Phonology Lab
>> Variation in Speech Perception
Researches under rublic of 'L2 speech perception' and 'cross-linguistic speech perception' have shown that members of different speech communities perceive speech sound differently. For example, monolingual Japanese adult listeners perform poorly in discriminating two English liquids [r] and [l], which is not contrastive phonemes in Japanese, while English speaking adults have no difficulties in the same task. One possible explanation of this state of affair is that human speech processing system is plastic, being shaped by previous linguistic experience. From this it follows that speech peception varies even among individuals within a single speech community, because no two individuals have identical linguistic experience. I'm currently exploring this aspect of variation, in conjunction with variation in speech production, as a potential explanatory factor in listener's misperception.
Some preliminary discussions are presented in the same manuscript:
"A Study on Perceptual Compensation for /u/-fronting in American English." 2009 Annual Report, UC Berkeley Phonology Lab (see link above.)
Past Projects
>> Effect of Phone Frequency on Speech Perception (with Keith Johnson)
Collaborating with Keith Johnson, I investigated the effect of phone frequency on stop place perception. The larger goal of this study was to study to what extent the listener’s linguistic experience influences speech perception. Since most of the previous research done on this topic has focused on the effect of phoneme inventory on phoneme identification and discrimination, we thought that it would be of interest to examine yet another source of linguistic experience, namely the frequency of occurrence of each of the phonemes in one’s language: some phonemes occur more often than others and the language users have more experience hearing certain sounds over others.
We conducted a series of three experiments to examine the effects of phoneme frequency on stop place perception by English-speaking and Japanese-speaking listeners. These two languages present an interesting test case, because in English [t] is more common than [k] while the opposite is true in Japanese. Sets of [VkV]-[VtV] place of articulation continua were created to test phoneme identification by the two groups of listeners. The results suggested that the more frequent sound in each language occupied a larger perceptual region along these continua.
This study was reported in:
"Frequency Effects in Cross-Linguistic Stop Place Perception: A Case of /t/-/k/ in Japanese and English." 2007 Annual Report, UC Berkeley Phonology Lab
>> Phonetics of Northern Paiute Stops
Based on a term project for Field Methods course taught by Prefessor Andrew Garrett, I conducted acoustic analysis of Northern Paiute stop contrast. Northern Paiute belongs to the Western Numic branch of the Uto-Aztecan language family, and some of its southern dialects have a unique three-way contrast in the medial obstruents: ‘fortis’, ‘lenis’, and what has been called by Numic specialists ‘voiced fortis’ series. Although the existence of this three-way contrast had been long recognized, a detailed study of their phonetic properties was scarce. Against this background, I conducted an acoustic study of the three-way contrast.
One unique aspect of the study was that I chose to analyze archived data taken from single speaker rather than current data from multiple speakers because I felt that archived material offers valuable speech data for the study of Northern Paiute, which is an endangered language. In endangered languages, linguistic properties tend to change so rapidly under the strong influence of dominant language. In such circumstances, archived speech materials might reveal some of the phonetic details which may or may not present in the current speech forms, or the speech data might represent unique regional variety which has already been lost. That is to say that archived materials have potential to serve as valuable and sometimes the only source of data that reveals diachronic and/or regional variations of the endangered language.
The findings of the study were reported in:
"Phonetic description of a three-way stop contrast in Northern Paiute."
Presentations
| 2009 | "A production study on phonologization of /u/-fronting in alveolar context." 83rd Annual Meeting of the Linguistic Society of America, San Francisco, California, January 10. [ppt] |
| "A study on perceptual compensation for /u/-fronting in American English." 35th Annual Meeting of the Berkeley Linguistics Society, Berkeley, California, February 14. [ppt] | |
| "A production study on phonologization of /u/-fronting in alveolar context." 157th Meeting of the Acoustical Society of America, Portland, Oregon, May 19. (poster session) [ppt] | |
| "Listener's variation in phonetic category boundary as a source of sound change: a case of /u/-fronting." 158th Meeting of the Acoustical Society of America, San Antonio, Texas, October 29. (poster session) | |
| 2008 | "Perceptual compensation for /u/-fronting in American English." 156th Meeting of the Acoustical Society of America, Miami, Florida, November 10. (poster session) [ppt] |
| 2007 | With Heriberto Averino, Eurie Shin, Sam Tilsen, and Jeff Pynes. “The Phonetics of Laryngealization in Yucatec Maya.” 81st Annual Meeting of the Linguistic Society of America, Anaheim, California, January 6. |
| “Phonetics of Mono Lake Paiute medial stops.” Annual Meeting of the Society for the Study of the Indigenous Languages of the Americas, Anaheim, CA, January 5. [ppt] | |
| 2006 | With Michael Houser and Maziar Toosarvandani. “Pluractional reduplication in Northern Paiute.” Friends of Uto-Aztecan Language Conference, University of Utah, Salt Lake City, August 23. |
With Molly Babel, Andrew Garrett, Erin Haynes, Michael Houser, Fanny Liu, Nicole Marcus, Ruth Rouvier, Ronald Sprouse, Angela Strom-Weber, and Mazia Toosarvandani. “A web accessible Mono Lake Paiute dictionary and text archive.” Friends of Uto-Aztecan Languages Conference, University of Utah, Salt Lake City, August 23. |
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| With Grace Dick and Erin Haynes. “A Mono Lake, Bridgeport, Coleville, & Sweetwater Northern Paiute Dictionary.” 8th Annual Great Basin Languages Conference, Bishop, California, October 23. | |
| 2005 | With Eurie Shin. “Studies on perceptual confusion on palatalized & labialized stops.” 79th Annual Meeting of the Linguistic Society of America, Oakland, California, January 6. |
Employment
>> Graduate Student Instuctor
| Spring 2009 | Ling 55 AC: The American Languages |
| Fall 2008 | Japanese 1A: Elementary Japanese |
>> Graduate Student Research Assistant
| 2006-2007 | Department of Linguistics, Supervisor: Keith Johnson |
| 2004-2006 | Survey of California and Other Indian Languages, Department of Linguisitcs, Supervisor: Leanne Hinton |
| 2003-2004 | Department of Linguistics, Supervisor: John Ohala |
>> Undergraduate Positions
| 2001-2003 | Undergraduate Student Research Assistant, Department of Linguisitcs, Supervisor: John Ohala |
| 2001 | Undergraduate Student Tutor, Japanese Language Program, Department of East Asian Languages and Cultures Supervisor: Chika Shibahara |