Asst. Professor
The University of California at Santa Cruz
Department of Linguistics
Stevenson Faculty Services
Santa Cruz, CA 95064
gmcguir1 (at) ucsc (dot) edu
I am generally interested in speech perception as it relates to phonetics and phonology. My current research is aimed at perceptual learning, phonetic categorization, and language specific perception. I have been tackling these issues through various training, discrimination, and classification experiments. I have also recently begun working on audio-visual perception in fricatives as well as the interaction of sex, gender, and attractiveness effects in speech processing.
Dimensions, distributions, and their effects on perceptual learning
This project, using both speech and non-speech stimuli, explores how selective attention to different dimensions affects categorization and sensitivity to contrasts. So far results demonstrate that attending to a dimension relevant to categorization increases sensitivity to that dimension relative to unattended dimensions. Moreover, how learning to attend to a dimension can generalize to new areas of perceptual space.
--Selective attention and English listeners' perceptual learning of the Polish post-alveolar sibilant contrast
--Orthographic effects on the attention to phonetic cues
--Selective attention and generalization of dimensions in speech-like stimuli (coming soon)
--Effects of the distribution of acoustic cues on infants' perception of sibilants
Cue covariance and the formation of higher-level perceptual units (with Angela Aiello, San Jose State U, and Ryan Bennett, UC Santa Cruz)
Certain speech cues are known to be integrated, or fused, into larger perceptual units. The reasons why some cues are integrable while others are separable is still controversial. The goal of this study is to examine the hypothesis that the predictable co-variance of cues drives integration, even when those cues have disparate perceptual effects or the gestures that give rise to them are not articulatorily related. (Two papers in prep, ask me about preliminary results)
The role of visual cues in non-sibilant fricative perception (with Molly Babel, U of British Columbia)
Though speech perception has generally focused on auditory cues, visual cues are known to play a significant role. This project examines how much visual cues contribute to the identification of a challenging contrast, /f/ 'deaf' and /th/ 'death'. These sounds are acoustically very similar, but have different visual cues. Across languages and various English dialects, /th/ frequently changes to /f/, but the reverse rarely happens. Our project examines the extent to which the salience of visual information contributes to the direction of this trend and how variability in talker saliency influences this effect.
--A cross-modal account for synchronic and diachronic patterns of /f/ and /theta/
Vocal attractiveness and sex stereotypicality (with Molly Babel, U of British Columbia, Joseph King and Teresa Miller, UC Santa Cruz)
This study examines the acoustic correlates of vocal attractiveness, i.e. what are the components of voices that makes them "attractive". Subsequent experiments currently underway touch on several related topics, e.g. the nature of attractiveness and whether there is a processing advantage to attractive voices, cross-cultural similarities and differences in attractive vocal qualities, and the relationship between attractiveness and stereotypicality.
--Acoustic determiners of vocal attractiveness go beyond apparent talker size
The phonetic effects of exercise-induced hyperpneic speech (with Sam Tilsen, U of Southern California)
This study examines the phonetic effects of hyperpneic, or out-of-breath speech. This condition is especially interesting because the strongest physical urge due to hyperpnea is not a need to inhale, but a need to exhale CO2. This conflicts with the need to maintain steady subglottal pressure for modal phonation. By putting in conflict these two needs we hope to better understand the roles of automaticity and control in speech production more generally. (In preparation.)
Exploring the causes of vowel dispersion (with Jaye Padgett, UC Santa Cruz)
While the shapes of vowel systems are often seen as the product of perceptual dispersion, the cause of this phenomenon is debated. Though Lindblom attributes dispersion to the communicative needs of speakers, others attribute it to automatic processes independent of communicative saliency. This project attempts to test these two concepts by examining dispersion over a brief time-course in a highly localized context.
Here's an essay on methods in speech perception that I wrote as a teaching aid. Please send me any comments and let me know if you found it useful!
--A Brief Primer on Experimental Designs for Speech Perception Research
I am currently teaching Phonology A (Graduate intro to phonetics and laboratory phonology) and Language and Social Identity. I have previously taught Phonetic Analysis (undergraduate phonetics) and a seminar in perceptual learning. I'll be teaching Introduction to Linguistics in the winter.