Charlotte Vaughn

Linguistic Processing of Accented Speech Across the Lifespan

In most of the world, people have regular exposure to multiple accents. Therefore, learning to quickly process accented speech is a prerequisite to successful communication. In this paper, we examine work on the perception of accented speech across the lifespan, from early infancy to late adulthood. Unfamiliar accents initially impair linguistic processing by infants, children, younger adults, and older adults, but listeners of all ages come to adapt to accented speech. Emergent research also goes beyond these perceptual abilities, by assessing links with production and the relative contributions of linguistic knowledge and general cognitive skills. We conclude by underlining points of convergence across ages, and the gaps left to face in future work.

The effects of lexical neighbors on stop consonant articulation.

Lexical neighbors (words sharing phonological structure with a target word) have been shown to influence the expression of phonetic contrasts for vowels and initial voiceless consonants. Focusing on minimal pair neighbors (e.g., bud-but), this research extends this work by examining the production of voiced as well as voiceless stops in both initial and final syllable/word position. The results show minimal pair neighbors can result both in enhancement and reduction of voicing contrasts (in initial vs final position), and differentially affect voiced vs voiceless consonants. These diverse effects of minimal pair neighbors serve to constrain interactive theories of language processing.

Operationalizing Linguistic Gratuity: From Principle to Practice

Although there is a well-established tradition of social engagement in sociolinguistics, there is little explicit discussion of the rationale, methods, and procedures for implementing the principle of linguistic gratuity. What approaches to the dissemination of sociolinguistic information must be adopted with communities and with the general public when language diversity is interpreted in terms of a prescriptive, correctionist model? What venues, activities, and products are the most effective in dialect awareness programs? And how does linguist– community collaboration work on a practical level? We consider theoretical, methodological, and practical issues in sociolinguistic engagement and dialect awareness outreach programs based on a range of experience in a variety of local and general public venues. The approach is based on the principle that the public is inherently curious about language differences and that this intrigue can be transformed into informal and formal public education. It is further premised on evidence that language differences can be linked to legitimate historical and cultural legacies, and that positively framed presentations of language differences in sociocultural and sociohistorical contexts can effectively counter dominant, seemingly unassailable ideologies in non-confrontational ways. A variety of venues are considered in collaborative engagement, including video documentaries, oral history CDs, museum exhibits, formal curricular programs, and popular trade books on language differences. Challenges in operationalizing linguistic gratuity include working with the community; balancing community linguistic expertise and community perspectives; design and audience, and practical logistical issues.

Perceptual integration of indexical information in bilingual speech

The present research examines how different types of indexical information, namely talker information and the language being spoken, are perceptually integrated in bilingual speech. Using a speeded classification paradigm (Garner, 1974), variability in characteristics of the talker (gender in Experiment 1 and specific talker in Experiment 2) and in the language being spoken (Mandarin vs. English) was manipulated. Listeners from two different language backgrounds, English monolinguals and Mandarin-English bilinguals, were asked to classify short, meaningful sentences obtained from different Mandarin-English bilingual talkers on these indexical dimensions. Results for the gender-language classification (Exp. 1) showed a significant, symmetrical interference effect for both listener groups, indicating that gender information and language are processed in an integral manner. For talker-language classification (Exp. 2), language interfered more with talker than vice versa for the English monolinguals, but symm...

Acoustic correlates of perceived southernness ratings

The Southern U.S. dialect and the Southern Vowel Shift (SVS), in particular, have been the subject of extensive research (e.g., Feagin, 1986; Labov, 1991; Fridland & Kendall, 2015), though there is limited work examining what acoustic cues trigger listeners to judge a speaker as sounding southern (cf. Fridland, Bartlett, & Kreuz, 2004; Allbritten, 2011). Fridland & Kendall (2012), and others, have used the Euclidean distance (ED) between the front vowels /e/ and /ɛ/ as a gradient metric of speakers’ degree of SVS shiftedness. While this was demonstrated to be a useful diagnostic in production, it has not been tested against listeners’ percepts of speakers’ southerness. This study asks: are listeners’ perceptions of southernness predicted by a speaker’s /e/-/ɛ/ ED, or other such measures? To test this question, we presented listeners with isolated words from both southern and western speakers. Listeners rated words on a 1–9 scale of how southern they sound. We assess whether southernness ratings are predic...

Re-Examining Phonetic Variability in Native and Non-Native Speech

Background/Aims: Non-native speech is frequently characterized as being more variable than native speech. However, the few studies that have directly investigated phonetic variability in the speech of second language learners have considered a limited subset of native/non-native language pairings and few linguistic features. Methods: The present study examines group-level withinspeaker variability and central tendencies in acoustic properties of vowels andstops produced by learners of Japanese from two native language backgrounds, English and Mandarin, as well as native Japanese speakers. Results: Results show that non-native speakers do not always exhibit more phonetic variability than native speakers, but rather that patterns of variability are specific to individual linguistic features and their instantiations in L1 and L2. Conclusion: Adopting this more nuanced approach to variability offers important enhancements to several areas of linguistic theory.

Comparative analysis of South Korean and North Korean vowels: A pilot study

This study investigates cardinal vowels of standard North Korean and South Korean. Prior reports have suggested that North and South Korean vowels have undergone changes after decades of relative isolation. This poster reports a pilot study investigating the ways in which the language standards of North and South Korea are similar and different by examining the speech of newscasters from each country. Acoustic analysis of the speech data suggested that North Korean vowels [ɛ] and [ae] were produced in the higher position relative to the South Korean counterparts, and the back vowels [ʌ] and [o] showed overlapping formant values unlike the South Korean counterparts. The perception experiment suggested that South Korean listeners could not accurately identify the North Korean [ʌ] and [o]. These results indicate that there may be interesting differences across North Korean and South Korean vowels.

Processing Relationships Between Language-Being-Spoken and Other Speech Dimensions in Monolingual and Bilingual Listeners:

While indexical information is implicated in many levels of language processing, little is known about the internal structure of the system of indexical dimensions, particularly in bilinguals. A series of three experiments using the speeded classification paradigm investigated the relationship between various indexical and non-linguistic dimensions of speech in processing. Namely, we compared the relationship between a lesser-studied indexical dimension relevant to bilinguals, which language is being spoken (in these experiments, either Mandarin Chinese or English), with: talker identity (Experiment 1), talker gender (Experiment 2), and amplitude of speech (Experiment 3). Results demonstrate that language-being-spoken is integrated in processing with each of the other dimensions tested, and that these processing dependencies seem to be independent of listeners’ bilingual status or experience with the languages tested. Moreover, the data reveal processing interference asymmetries, suggesting a processing hierarchy for indexical, non-linguistic speech features.

Context effects on accentedness ratings

Intelligibility and accentedness are largely independent judgments (Derwing & Munro, 1995); a speaker rated as highly accented can be quite intelligible. The context of listeners’ exposure to accented speakers has been shown to affect adaptation to speakers in terms of intelligibility (e.g., Tzeng et al., 2016), suggesting that implicit comparison between examples facilitates learning of systematic properties of accented speech. However, it is unknown whether context affects accentedness ratings, which are often assumed to be stable properties of speakers. To better understand the susceptibility of accent ratings to context effects, the present study examines listeners’ accentedness judgments of native and non-native speech taken from the ALLSSTAR Corpus (Bradlow et al., 2010). A target set of the same accented speech samples was embedded in a variety of task contexts, varying whether the stimuli were randomized among speakers or blocked by speaker, or presented at the beginning or end of the experiment. ...

Do Listeners Learn Better from Natural Speech

Perceptual learning of novel pronunciations is a seemingly robust and efficient process for adapting to unfamiliar speech patterns. In this study we compare perceptual learning of /s/ words where a medially occurring /s/ is substituted with /S/, rendering, for example, castle as /kæSl/ instead of /kæsl/. Exposure to the novel pronunciations is presented in the guise of a lexical decision task. Perceptual learning is assessed in a categorization task where listeners are presented with minimal pair continua (e.g., sock-shock). Given recent suggestions that perceptual learning may be more robust with natural as opposed to synthesized speech, we compare perceptual learning in groups that either receive natural /s/-to-/S/ words or resynthesized /s/-to-/S/ words. Despite low word endorsement rates in the lexical decision task, both groups of listeners show robust generalization in perceptual learning to the novel minimal pair continua, thereby indicating that at least with high quality resynthesis, perceptual learning in natural and synthesized speech is roughly equivalent.