Biomedical subjects

Cynthia G Clopper

Publications and source records attributed to Cynthia G Clopper.

5 recordsLinked to original sources

PubMed2006

Perceptual similarity of regional dialects of American English.

Previous research on the perception of dialect variation has measured the perceptual similarity of talkers based on regional dialect using only indirect methods. In the present study, a paired comparison similarity ratings task was used to obtain direct measures of perceptual similarity. Naive listeners were asked to make explicit judgments about the similarity of a set of talkers based on regional dialect. The talkers represented four regional varieties of American English and both genders. Results revealed an additive effect of gender and dialect on mean similarity ratings and two primary dimensions of perceptual dialect similarity: geography (northern versus southern varieties) and dialect markedness (many versus few characteristic properties). The present findings are consistent with earlier research on the perception of dialect variation, as well as recent speech perception studies which demonstrate the integral role of talker gender in speech perception.

Acoustic Stimulation↗

PubMed2006

Effects of open-set and closed-set task demands on spoken word recognition.

Closed-set tests of spoken word recognition are frequently used in clinical settings to assess the speech discrimination skills of hearing-impaired listeners, particularly children. Speech scientists have reported robust effects of lexical competition and talker variability in open-set tasks but not closed-set tasks, suggesting that closed-set tests of spoken word recognition may not be valid assessments of speech recognition skills. The goal of the current study was to explore some of the task demands that might account for this fundamental difference between open-set and closed-set tasks. In a series of four experiments, we manipulated the number and nature of the response alternatives. Results revealed that as more highly confusable foils were added to the response alternatives, lexical competition and talker variability effects emerged in closed-set tests of spoken word recognition. These results demonstrate a close coupling between task demands and lexical competition effects in lexical access and spoken word recognition processes.

Adolescent↗

PubMed2005

Acoustic characteristics of the vowel systems of six regional varieties of American English.

Previous research by speech scientists on the acoustic characteristics of American English vowel systems has typically focused on a single regional variety, despite decades of sociolinguistic research demonstrating the extent of regional phonological variation in the United States. In the present study, acoustic measures of duration and first and second formant frequencies were obtained from five repetitions of 11 different vowels produced by 48 talkers representing both genders and six regional varieties of American English. Results revealed consistent variation due to region of origin, particularly with respect to the production of low vowels and high back vowels. The Northern talkers produced shifted low vowels consistent with the Northern Cities Chain Shift, the Southern talkers produced fronted back vowels consistent with the Southern Vowel Shift, and the New England, Midland, and Western talkers produced the low back vowel merger. These findings indicate that the vowel systems of American English are better characterized in terms of the region of origin of the talkers than in terms of a single set of idealized acoustic-phonetic baselines of "General" American English and provide benchmark data for six regional varieties.

Adolescent↗

PubMed2004

Effects of talker variability on perceptual learning of dialects.

Two groups of listeners learned to categorize a set of unfamiliar talkers by dialect region using sentences selected from the TIMIT speech corpus. One group learned to categorize a single talker from each of six American English dialect regions. A second group learned to categorize three talkers from each dialect region. Following training, both groups were asked to categorize new talkers using the same categorization task. While the single-talker group was more accurate during initial training and test phases when familiar talkers produced the sentences, the three-talker group performed better on the generalization task with unfamiliar talkers. This cross-over effect in dialect categorization suggests that while talker variation during initial perceptual learning leads to more difficult learning of specific exemplars, exposure to intertalker variability facilitates robust perceptual learning and promotes better categorization performance of unfamiliar talkers. The results suggest that listeners encode and use acoustic-phonetic variability in speech to reliably perceive the dialect of unfamiliar talkers.

Adult↗

PubMed2002

Prosodic effects on word reduction.

It is widely known that English-speaking children reduce words by omitting syllables in certain predictable patterns (e.g., banána --> nána). One way to better understand the nature of phonological reductions in children is to examine adults' word reduction behavior. This study explored whether adults produce predictable output patterns when reducing words. Undergraduate participants heard a list of polysyllabic words varying systematically across syllable number and primary stress location and were asked to generate a "reduced" form, similar to common English reductions (e.g., rhinóceros --> rhino). Regardless of stress and syllable number, participants reduced the stimulus words significantly more often to left-headed disyllabic or monosyllabic feet, retaining stressed syllables and omitting unstressed syllables. The general bias found was similar to that which children exhibit in natural speech, namely, to maintain well-formed prosodic patterns and preserve salient syllables. On the other hand, a tendency to preserve word-initial instead of word-final syllables was also found, suggesting subtle differences in language processing between children and adults. The current study contributes to the psycholinguistic literature on adults' syllable omissions in abbreviations and fast-speech registers by examining the processing strategies that adults may use when reducing words.

Adult↗