Megha Sundara

A cross-language comparison of /d /–/ð / perception: Evidence for a new developmental pattern

Previous studies have shown that infants perceptually differentiate certain non-native contrasts at 6-8 months but not at 10-12 months of age, whereas differentiation is evident at both ages in infants for whom the test contrasts are native. These findings reveal a language-specific bias to be emerging during the first year of life. A developmental decline is not observed for all non-native contrasts, but it has been consistently reported for every contrast in which language effects are observed in adults, In the present study differentiation of English /d-th/ by English- and French-speaking adults and English- and French-learning infants at two ages (6-8 and 10-12 months) was compared using the conditioned headturn procedure. Two findings emerged. First, perceptual differentiation was unaffected by language experience in the first year of life, despite robust evidence of language effects in adulthood. Second, language experience had a facilitative effect on performance after 12 months, whereas performance remained unchanged in the absence of specific language experience. These data are clearly inconsistent with previous studies as well as predictions based on a conceptual framework proposed by Burnham [Appl. Psycholing. 7, 201-240 (1986)]. Factors contributing to these developmental patterns include the acoustic properties of /d-th/, the phonotactic uniqueness of English /th/, and the influence of lexical knowledge on phonetic processing.

Language-experience facilitates discrimination of /d- / in monolingual and bilingual acquisition of English

To trace how age and language experience shape the discrimination of native and non-native phonetic contrasts, we compared 4-year-olds learning either English or French or both and simultaneous bilingual adults on their ability to discriminate the English /d-th/ contrast. Findings show that the ability to discriminate the native English contrast improved with age. However, in the absence of experience with this contrast, discrimination of French children and adults remained unchanged during development. Furthermore, although simultaneous bilingual and monolingual English adults were comparable, children exposed to both English and French were poorer at discriminating this contrast when compared to monolingual English-learning 4-year-olds. Thus, language experience facilitates perception of the English /d-th/ contrast and this facilitation occurs later in development when English and French are acquired simultaneously. The difference between bilingual and monolingual acquisition has implications for language organization in children with simultaneous exposure.

Development of coronal stop perception: Bilingual infants keep pace with their monolingual peers

Previous studies indicate that the discrimination of native phonetic contrasts in infants exposed to two languages from birth follows a different developmental time course from that observed in monolingual infants. We compared infant discrimination of dental (French) and alveolar (English) place variants of /d/ in three groups differing in language experience. At 6-8 months, infants in all three language groups succeeded; at 10-12 months, monolingual English and bilingual but not monolingual French infants distinguished this contrast. Thus, for highly frequent, similar phones, despite overlap in cross-linguistic distributions, bilingual infants performed on par with their English monolingual peers and better than their French monolingual peers.

Observation-execution matching system for speech: a magnetic stimulation study

Observation of limb movements in human subjects resulted in increased motor-evoked potential (MEP) amplitude elicited by magnetic stimulation of motor cortex in the muscles involved in that movement, suggesting that an observation–execution matching (OEM) system exists in humans. We investigated whether the OEM system is activated by speech gestures presented in the visual and auditory modalities. We found that visual observation of speech movement enhanced MEP ampli- tude specifically in muscles involved in production of the observed speech. In contrast, listening to the sound did not produce MEP enhancement. The findings suggest that the OEM system may be modality specific. It may be involved in action recognition in the visual modality, but is not responsible for perception of simple items of sound.

Production of Coronal Stops by Simultaneous Bilingual Adults.

This study investigated acoustic-phonetics of coronal stop production by adult simultaneous bilingual and monolingual speakers of Canadian English (CE) and Canadian French (CF). Differences in the phonetics of CF and CE include voicing and place of articulation distinctions. CE has a two-way voicing distinction (in syllable initial position) contrasting short-and long-lag VOT; coronal stops in CE are described as alveolar. CF also has a two-way voicing distinction, but contrasting lead and short-lag VOT; coronal stops in CF are described as dental. Acoustic analyses of stop consonants for both VOT and dental/alveolar place of articulation are reported. Results indicate that simultaneous bilingual as well as monolingual adults produce language-specific differences, albeit not in the same way, across CF and CE for voicing and place. Similarities and differences between simultaneous bilingual and monolingual adults are discussed to address phonological organization in simultaneous bilingual adults.

Rhythmic distance between languages affects the development of speech perception in bilingual infants

Abstract The time course and trajectory of development of phonetic perception in Spanish–Catalan bilingual and monolingual infants is different ( Bosch & Sebastian-Galles (2003a) , Bosch & Sebastian-Galles (2003b) , Bosch & Sebastian-Galles (2005) ; Sebastian-Galles & Bosch, 2009 ). Bosch and Sebastian-Galles argue that, at least initially, bilingual infants track statistical regularities across the two languages, leading to their temporary inability to discriminate acoustically similar phonetic categories. In this paper, we test bilingual Spanish–English 4- and 8-month-olds’ discrimination of vowels. Results indicate that, when the two languages being learned are rhythmically dissimilar, bilingual infants are able to discriminate acoustically similar vowel contrasts that are phonemic in one, but not the other language, at an earlier age. These results substantiate a mechanism of language tagging or sorting; such a mechanism is likely to help bilingual infants calculate statistics separately for the two languages.

Discrimination of coronal stops by bilingual adults: The timing and nature of language interaction

The current study was designed to investigate the timing and nature of interaction between the two languages of bilinguals. For this purpose, we compared discrimination of Canadian French and Canadian English coronal stops by simultaneous bilingual, monolingual and advanced early L2 learners of French and English. French /d/ is phonetically described as dental whereas English /d/ is described as alveolar. Using a categorial AXB task, the performance of all four groups was compared to chance and to the performance of native Hindi listeners. Hindi listeners performed well above chance in discriminating French and English /d/-initial syllables. The discrimination performance of advanced early L2 learners, but not simultaneous bilinguals, was consistent with one merged category for coronal stops in the two languages. The data provide evidence for interaction in L2 learners as well as simultaneous bilinguals; however, the nature of the interaction is different in the two groups.

Acoustic-phonetics of coronal stops: A cross-language study of Canadian English and Canadian French

The study was conducted to provide an acoustic description of coronal stops in Canadian English (CE) and Canadian French (CF). CE and CF stops differ in VOT and place of articulation. CE has a two-way voicing distinction (in syllable initial position) between simultaneous and aspirated release; coronal stops are articulated at alveolar place. CF, on the other hand, has a two-way voicing distinction between prevoiced and simultaneous release; coronal stops are articulated at dental place. Acoustic analyses of stop consonants produced by monolingual speakers of CE and of CF, for both VOT and alveolar/dental place of articulation, are reported. Results from the analysis of VOT replicate and confirm differences in phonetic implementation of VOT across the two languages. Analysis of coronal stops with respect to place differences indicates systematic differences across the two languages in relative burst intensity and measures of burst spectral shape, specifically mean frequency, standard deviation, and kurtosis. The majority of CE and CF talkers reliably and consistently produced tokens differing in the SD of burst frequency, a measure of the diffuseness of the burst. Results from the study are interpreted in the context of acoustic and articulatory data on coronal stops from several other languages.

The role of language experience in word segmentation: A comparison of English, French, and bilingual infants

English‐learning and French‐learning 7.5‐month‐old infants were tested using the headturn preference procedure on their ability to segment bisyllabic words in both English and French. In the English condition infants were familiarized with trochaic bisyllables, the predominant stress pattern found in English, and then presented English passages with and without the familiarized words. In the French condition, infants were familiarized with iambic bisyllables, the characteristic word stress pattern found in French, and were then presented French passages with and without the familiarized words. Findings indicate that by 7.5 months of age, infants’ learning either a syllable‐timed (French) or a stressed‐timed language (English) can segment bisyllabic words with the predominant stress pattern of their native language. However, French infants fail to segment English trochaic words from English passages; data on English infants’ segmentation in the French condition are forthcoming. If both groups fail to segment in a rhythmically different non‐native language, it will confirm that word segmentation abilities of 7.5‐month‐old infants are influenced by the prosodic structure of the native language. Preliminary results obtained from infants who are regularly exposed to both languages will also be reported.

Biased generalization of newly learned phonological alternations by 12-month-old infants

Previous work has suggested that learners are sensitive to phonetic similarity when learning phonological patterns (e.g., Steriade, 2001/2008; White, 2014). We tested 12-month-old infants to see if their willingness to generalize newly learned phonological alternations depended on the phonetic similarity of the sounds involved. Infants were exposed to words in an artificial language whose distributions provided evidence for a phonological alternation between two relatively dissimilar sounds ([p∼v] or [t∼z]). Sounds at one place of articulation (labials or coronals) alternated whereas sounds at the other place of articulation were contrastive. At test, infants generalized the alternation learned during exposure to pairs of sounds that were more similar ([b∼v] or [d∼z]). Infants in a control group instead learned an alternation between similar sounds ([b∼v] or [d∼z]). When tested on dissimilar pairs of sounds ([p∼v] or [t∼z]), the control group did not generalize their learning to the novel sounds. The results are consistent with a learning bias favoring alternations between similar sounds over alternations between dissimilar sounds.