Bronwen G. Evans

Comprehension of familiar and unfamiliar native accents under adverse listening conditions.

This study aimed to determine the relative processing cost associated with comprehension of an unfamiliar native accent under adverse listening conditions. Two sentence verification experiments were conducted in which listeners heard sentences at various signal-to-noise ratios. In Experiment 1, these sentences were spoken in a familiar or an unfamiliar native accent or in two familiar native accents. In Experiment 2, they were spoken in a familiar or unfamiliar native accent or in a nonnative accent. The results indicated that the differences between the native accents influenced the speed of language processing under adverse listening conditions and that this processing speed was modulated by the relative familiarity of the listener with the native accent. Furthermore, the results showed that the processing cost associated with the nonnative accent was larger than for the unfamiliar native accent.

Plasticity in vowel perception and production: A study of accent change in young adults

This study investigated changes in vowel production and perception among university students from the north of England, as individuals adapt their accent from regional to educated norms. Subjects were tested in their production and perception at regular intervals over a period of 2 years: before beginning university, 3 months later, and at the end of their first and second years at university. At each testing session, subjects were recorded reading a set of experimental words and a short passage. Subjects also completed two perceptual tasks; they chose best exemplar locations for vowels embedded in either northern or southern English accented carrier sentences and identified words in noise spoken with either a northern or southern English accent. The results demonstrated that subjects at a late stage in their language development, early adulthood, changed their spoken accent after attending university. There were no reliable changes in perception over time, but there was evidence for a between-subjects link between production and perception; subjects chose similar vowels to the ones they produced, and subjects who had a more southern English accent were better at identifying southern English speech in noise.

Learning English vowels with different first-language vowel systems: Perception of formant targets, formant movement, and duration

This study examined whether individuals with a wide range of first-language vowel systems (Spanish, French, German, and Norwegian) differ fundamentally in the cues that they use when they learn the English vowel system (e.g., formant movement and duration). All subjects: (1) identified natural English vowels in quiet; (2) identified English vowels in noise that had been signal processed to flatten formant movement or equate duration; (3) perceptually mapped best exemplars for first- and second-language synthetic vowels in a five-dimensional vowel space that included formant movement and duration; and (4) rated how natural English vowels assimilated into their L1 vowel categories. The results demonstrated that individuals with larger and more complex first-language vowel systems (German and Norwegian) were more accurate at recognizing English vowels than were individuals with smaller first-language systems (Spanish and French). However, there were no fundamental differences in what these individuals learned. That is, all groups used formant movement and duration to recognize English vowels, and learned new aspects of the English vowel system rather than simply assimilating vowels into existing first-language categories. The results suggest that there is a surprising degree of uniformity in the ways that individuals with different language backgrounds perceive second language vowels.

Auditory Training for Experienced and Inexperienced Second-Language Learners: Native French Speakers Learning English Vowels.

This study examined whether high-variability auditory training on natural speech can benefit experienced second-language English speakers who already are exposed to natural variability in their daily use of English. The subjects were native French speakers who had learned English in school; experienced listeners were tested in England and the less experienced listeners were tested in France. Both groups were given eight sessions of high-variability phonetic training for English vowels, and were given a battery of perception and production tests to evaluate their improvement. The results demonstrated that both groups learned to similar degrees, suggesting that training provides a type of learning that is distinct from that obtained in more naturalistic situations.

Vowel recognition via cochlear implants and noise vocoders: Effects of formant movement and duration

Previous work has demonstrated that normal-hearing individuals use fine-grained phonetic variation, such as formant movement and duration, when recognizing English vowels. The present study investigated whether these cues are used by adult postlingually deafened cochlear implant users, and normal-hearing individuals listening to noise-vocoder simulations of cochlear implant processing. In Experiment 1, subjects gave forced-choice identification judgments for recordings of vowels that were signal processed to remove formant movement and/or equate vowel duration. In Experiment 2, a goodness-optimization procedure was used to create perceptual vowel space maps (i.e., best exemplars within a vowel quadrilateral) that included F1, F2, formant movement, and duration. The results demonstrated that both cochlear implant users and normal-hearing individuals use formant movement and duration cues when recognizing English vowels. Moreover, both listener groups used these cues to the same extent, suggesting that postlingually deafened cochlear implant users have category representations for vowels that are similar to those of normal-hearing individuals.

Category and perceptual interference in second-language phoneme learning: an examination of English /w/-/v/ learning by Sinhala, German, and Dutch speakers.

The present study investigated the perception and production of English /w/ and /v/ by native speakers of Sinhala, German, and Dutch, with the aim of examining how their native language phonetic processing affected the acquisition of these phonemes. Subjects performed a battery of tests that assessed their identification accuracy for natural recordings, their degree of spoken accent, their relative use of place and manner cues, the assimilation of these phonemes into native-language categories, and their perceptual maps (i.e., multidimensional scaling solutions) for these phonemes. Most Sinhala speakers had near-chance identification accuracy, Germans ranged from chance to 100% correct, and Dutch speakers had uniformly high accuracy. The results suggest that these learning differences were caused more by perceptual interference than by category assimilation; Sinhala and German speakers both have a single native-language phoneme that is similar to English /w/ and /v/, but the auditory sensitivities of Sinhala speakers make it harder for them to discern the acoustic cues that are critical to /w/-/v/ categorization.

Acquiring a second language in an immigrant community: The production of Sylheti and English stops and vowels by London-Bengali speakers

Abstract This study investigated the production of the heritage language (L1) and the host language (L2) in an immigrant community. Specifically, the study focused on the production of Sylheti (L1) and English (L2) stops and vowels by speakers from the London-Bengali community. Speakers had been resident in the UK for similar lengths of time, but had arrived in the host country at different ages. Speakers were recorded producing Sylheti and English bilabial, alveolar and velar stops in word-initial stressed position and Sylheti and English monophthongal vowels. Acoustic analyses of stop consonants (VOT) and monophthongal vowels (formants and duration) are reported. The results demonstrated that the Late arrivals produced Sylheti stops and vowels in a native-like way, but that their English categories reflected their Sylheti productions. In contrast, the Early arrivals and speakers who were born in the UK (second-generation) used native-like categories for Sylheti vowels but not for Sylheti stops. For English their production was similar to that of the Standard Southern British English speakers. These findings provide an insight into the phonetic organization of speakers from immigrant communities such as the London-Bengali community.

Plasticity in speech production and perception: A study of accent change in young adults

This study investigated plasticity in speech production and perception among university students, as individuals change their accent from regional to educated norms. Subjects were tested before beginning university, 3 months later and on completion of their first year of study. At each stage they were recorded reading a set of test words and a short passage. They also completed two perceptual tasks; they found best exemplar locations for vowels embedded in carrier sentences and identified words in noise. The results demonstrated that subjects changed their spoken accent after attending university. The changes were linked to sociolinguistic factors; subjects who were highly motivated to fit in with their university community changed their accent more. There was some evidence for a link between production and perception; between‐subject differences in production and perception were correlated. However, this relationship was weaker for within‐subject changes in accent over time. The results suggest that ther...

Vocal Tract Images Reveal Neural Representations of Sensorimotor Transformation During Speech Imitation

&NA; Imitating speech necessitates the transformation from sensory targets to vocal tract motor output, yet little is known about the representational basis of this process in the human brain. Here, we address this question by using real‐time MR imaging (rtMRI) of the vocal tract and functional MRI (fMRI) of the brain in a speech imitation paradigm. Participants trained on imitating a native vowel and a similar nonnative vowel that required lip rounding. Later, participants imitated these vowels and an untrained vowel pair during separate fMRI and rtMRI runs. Univariate fMRI analyses revealed that regions including left inferior frontal gyrus were more active during sensorimotor transformation (ST) and production of nonnative vowels, compared with native vowels; further, ST for nonnative vowels activated somatomotor cortex bilaterally, compared with ST of native vowels. Using test representational similarity analysis (RSA) models constructed from participants’ vocal tract images and from stimulus formant distances, we found that RSA searchlight analyses of fMRI data showed either type of model could be represented in somatomotor, temporal, cerebellar, and hippocampal neural activation patterns during ST. We thus provide the first evidence of widespread and robust cortical and subcortical neural representation of vocal tract and/or formant parameters, during prearticulatory ST.

English vowel training with different first‐language vowel systems

This study examined whether native speakers of Spanish and German learn differently when given auditory training for English vowels. Spanish has fewer vowels (5) than does German (18). Spanish speakers thus need to acquire more vowel categories when learning English than do Germans, but the relative sparseness of the Spanish vowel space may actually facilitate learning (i.e., there is more room for new categories). Prior to training, the Spanish and German speakers were matched between groups in terms of their English vowel identification accuracy. Each subject completed a battery of pre/post‐training tests (e.g., English vowel identification in quiet and noise; perceptual mapping of best exemplars) and were given five sessions of high‐variability vowel identification training. The results demonstrated that the German subjects improved more in their English vowel identification accuracy (average 20 percentage‐point improvement) than did the Spanish subjects (average ten percentage‐point improvement). It a...