Research
The current research projects being conducted at SPA Labs are unified in a search for a better understanding of behavioral and cognitive processes involved in human communication such as cross-generaltional sound transmission, human perception of speech dynamics, and phonetic category learning. A description of each project and work progress is linked to below.
Cross-generational sound change in American English
This research examines sound change over time, a widespread feature in human language, which is discernible in speech of each upcoming generation of speakers from the same dialectal background. The investigation focuses on vowel changes across generations of speakers of three different dialects of American English and seeks to provide at least a partial explanation for why such changes occur.
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Markedness and learnability in second language phonology
The aim of this research is to understand the interaction of the rules of phonology and the morphemic properties of language in a way sufficient to formulate predictions about staged development of second language phonetic category formation. The perceptual relevance of the universal principles of phonology to phonetic processing and category learning is examined in a set of identification with masking and descrimination experiments. (More)
Speech tempo across dialect, age and gender
Humans vary in how they produce speech and those differences can depend on a number of factors.
This project examines variation in speech tempo related to speaker age, gender and geographic region of origin. (More)
Variation in vowel space across dialects and generations
The position and distribution of vowels within a speaker's vowel space varies significantly across regional varieties of American English as well as across different generations of speakers. This research examines the effect these different distributions have on the size and extent of the acoustic vowel space (which can be seen as a measure of the "acoustic workspace" used by a speaker. (More)
Speech intelligibility in cross-dialectal multi-talker babble
The presence of background noise (in the form of speech babble) results in a reduction in speech intelligibility.
This study aims to better understand both energetic and informational masking that occurs in daily speech-in-speech perception.
The informational masking could be due to a whole-word effect, sub-lexical effects, or a prosodic effect.
This study examines speech perception in multi-talker babble by varying speaker dialect as a masker.
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Acquisition of the s/sh contrast in English by native Korean speakers
The present study examines the production of the English s/sh distinction (in both derived and underived contexts) by native speakers of Korean both before and after a short (one-hour) computer-controlled training session. Of interest is the extent to which the values of the spectral moments of the fricative become more English-like. (More)
Dissertations in progress