Here are descriptions of some of the research projects
that I'm currently working on.
Cross-linguistic studies on speech perception
One key observation at the intersection of speech perception
theory and phonology is that language experience influences speech
perception. This project seeks to understand (1) what aspects of
speech perception adapt to experience and (2) how pervasive this
adaptation may be. Answers to these questions bear on speech
perception theory, so that models need to be able to account for both
cross-linguistic regularities in speech perception and for
language-specific aspects of perception. Similarly, the linguistic
theory of phonology and language sound change may also be impacted by
our understanding of the maleability of speech perception.
This project has grown out of a very productive and influential
(for me) collaboration with Beth Hume (OSU Linguistics). In that
collaboration we edited a couple of books, and
wrote several papers:
The Role of Speech Perception in Phonology (Hume & Johnson)
The Impact of
Partial Phonological Contrast on Speech Perception (Hume & Johnson)
A model of the
interplay of speech perception and phonology (Hume & Johnson)
A cross-linguistic study of place perception
(Hume et al.)
Adaptive dispersion in
vowel perception (Johnson)
Huang Tsan wrote her dissertation on
the perception of tone and tone sandhi by speakers of Mandarin Chinese
and American English. One thing that I think is very interesting
about her studies is that the influence of language on perception
seems to be present in very low-level psychoacoustic processing.
Also, be sure to check out Steve
Winters' research on place perception and place assimilation
processes. Including his PhD thesis Empirical
investigations into the perceptual and articulatory origins of
cross-Linguistic asymmetries in place assimilation
ViC - Variation in Conversation.
Mark Pitt (OSU Psychology) and I, together with Beth Hume (OSU
Linguistics) and Eric Fosler-Lussier (OSU Computer Science), have been
working on a large corpus of conversational speech (the speakers are
all natives of Columbus Ohio so we sometimes call it the "Buckeye
Corpus"). This work is funded by the NIH and resulted in a number of
research papers, as well as its own web-page.
No, it isn't a cross between the X-Files and the
Mod-squad, it's just a computational model of speech perception that
draws on techniques in automatic speech recognition and ideas from
mathematical psychology to model human auditory word
recognition. X-MOD uses exemplar-based categorical
representations of words, where each exemplar is like a LAFS spectral
sequence network (Klatt, 1980). One of the more interesting
things that happens in X-MOD word recognition is that smaller units of
linguistic structure - such as syllables and segments emerge in the
recognition process - and like word categories, these units are
defined simply as sets of exemplars. Of course, given my
interest in processes of speaker normalization in speech perception,
X-MOD handles talker differences beautifully. An early non-DSP
implementation was presented in the Johnson & Mullennix
volume. The more recent model, complete with auditory neural
spectrograms, is described in a paper in Volume 50 of the OSU Working Papers in
Phonetic studies of the languages of Oklahoma
The goal of this project is to produce acoustic/phonetic descriptions
of some of the languages of Oklahoma. Phonetic descriptions of endangered
languages are a valuable contribution to the cross-linguistic study phonetics.
We also are producing descriptions that can be of value in the design of
language teaching materials - returning something to the speakers of the
I also like this project because it gives me opportunities
to return 'home' (I am a native Oklahoman) and visit with my family
and friends there.
Creek. I am working with several colaborators on this project.
Martin (College of William and Mary) is an expert on the Creek language.
Mauldin he is producing a dictionary of Creek. Jack and I have written
a paper on the vowels of Creek (download "Vowel
reduction in Creek" PDF 128k) and are working on papers on the consonants
and tone patterns. Here's
a photo of us at Margaret's house.
Cherokee. Marcia Haag (University of Oklahoma) is an expert on syntax and morphology
in native American languages. She has published a dictionary of Choctaw.
Durbin Feeling (Northeastern Oklahoma State) is an expert on Cherokee and
together with William Pulte produced a famous dictionary of Cherokee. We
are working together on a phonetic study of Cherokee - especially the tonal
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