Classes Of Speech Sounds Research Articles

Perceptual adaptation to nonnative speech by school-aged children

With training, listeners can improve their understanding of speech in adverse listening conditions, including those stemming from the environment (e.g., competing noise) and the talker (e.g., unfamiliar accents). For example, listeners can increase their ability to understand a specific nonnative talker and, when trained with multiple talkers with the same nonnative accent, can generalize their learning to novel talkers with that accent. The current study extends these findings by investigating children’s perceptual adaptation to nonnative speech. School-aged children can retune specific speech sound category boundaries, but little is known about their abilities to adapt to naturally produced nonnative speech. To assess children’s adaptation to nonnative speech, 6- and 9-year-old children were presented with sentences produced by multiple Mandarin-accented talkers and repeated what they heard (training condition) or were not given training (control condition). A posttest assessed their understanding of se...

Consolidation during sleep stabilizes non-native speech sound learning

Learning to perceive non-native speech sound categories is a challenge for many adult listeners. Even after successful learning, individuals vary in the degree to which they can successfully retain and consolidate learned perceptual categories in memory. In this talk, I describe a recent line of work from our lab showing that sleep plays a greater role in perceptual learning of non-native speech sounds than previously supposed. Specifically, we find that consolidation processes during overnight sleep protect learned phonetic information from interference from similar sounds from one's native language. I will discuss the potential sources of native language interference by reviewing a series of studies that test the low-level acoustic and abstract phonological contributions to interference. Finally, overnight gains in performance can be specifically linked to the duration and quality of sleep, suggesting a key role for sleep, per se, in the retention of non-native speech categories over multiple sessions. Taken together, this line of research suggests that individual variability in non-native speech sound learning may in part be linked to individual differences in sleep behavior and differences in the degree of pre-sleep exposure to competing native-language phonetic contrasts.

Minimal pair word learning and vocabulary size: Links with later language skills

ABSTRACTThere is increasing interest in the link between early linguistic skills and later language development. In a longitudinal study, we investigated infants’ (a) ability to use speech sound categories to guide word learning in the habituation-based minimal pair switch task, and (b) early productive vocabulary, related to their concurrent and later language task performance. The participants at Phase 1 were 64 infants aged 16–24 months (25 with familial risk of language/speech impairment), followed up at 27 months (Phase 2) and at 3 years (Phase 3). Phase 1 productive vocabulary was correlated with Phase 2 productive vocabulary, and with concurrent and later (Phase 3) tests of language production and comprehension scores (standardized tool), and phonology. Phase 1 switch task performance was correlated with concurrent productive vocabulary and language production scores, but not by Phase 3. However, a combination of early low vocabulary score and a preference for looking at an already-habituated word–object combination in the switch task may show some promise as an identifier for early speech–language intervention. We discuss how these relations can help us better understand the foundations of word learning.

A unified account of categorical effects in phonetic perception.

Categorical effects are found across speech sound categories, with the degree of these effects ranging from extremely strong categorical perception in consonants to nearly continuous perception in vowels. We show that both strong and weak categorical effects can be captured by a unified model. We treat speech perception as a statistical inference problem, assuming that listeners use their knowledge of categories as well as the acoustics of the signal to infer the intended productions of the speaker. Simulations show that the model provides close fits to empirical data, unifying past findings of categorical effects in consonants and vowels and capturing differences in the degree of categorical effects through a single parameter.

Linguistic category structure influences early auditory processing: Converging evidence from mismatch responses and cortical oscillations

While previous research has established that language-specific knowledge influences early auditory processing, it is still controversial as to what aspects of speech sound representations determine early speech perception. Here, we propose that early processing primarily depends on information propagated top–down from abstractly represented speech sound categories. In particular, we assume that mid-vowels (as in ‘bet’) exert less top–down effects than the high-vowels (as in ‘bit’) because of their less specific (default) tongue height position as compared to either high- or low-vowels (as in ‘bat’). We tested this assumption in a magnetoencephalography (MEG) study where we contrasted mid- and high-vowels, as well as the low- and high-vowels in a passive oddball paradigm. Overall, significant differences between deviants and standards indexed reliable mismatch negativity (MMN) responses between 200 and 300ms post-stimulus onset. MMN amplitudes differed in the mid/high-vowel contrasts and were significantly reduced when a mid-vowel standard was followed by a high-vowel deviant, extending previous findings. Furthermore, mid-vowel standards showed reduced oscillatory power in the pre-stimulus beta-frequency band (18–26Hz), compared to high-vowel standards. We take this as converging evidence for linguistic category structure to exert top–down influences on auditory processing. The findings are interpreted within the linguistic model of underspecification and the neuropsychological predictive coding framework.

Syllable Structure Universals and Native Language Interference in Second Language Perception and Production: Positional Asymmetry and Perceptual Links to Accentedness.

The present study investigated how syllable structure differences between the first Language (L1) and the second language (L2) affect L2 consonant perception and production at syllable-initial and syllable-final positions. The participants were Mandarin-speaking college students who studied English as a second language. Monosyllabic English words were used in the perception test. Production was recorded from each Chinese subject and rated for accentedness by two native speakers of English. Consistent with previous studies, significant positional asymmetry effects were found across speech sound categories in terms of voicing, place of articulation, and manner of articulation. Furthermore, significant correlations between perception and accentedness ratings were found at the syllable onset position but not for the coda. Many exceptions were also found, which could not be solely accounted for by differences in L1–L2 syllabic structures. The results show a strong effect of language experience at the syllable level, which joins force with acoustic, phonetic, and phonemic properties of individual consonants in influencing positional asymmetry in both domains of L2 segmental perception and production. The complexities and exceptions call for further systematic studies on the interactions between syllable structure universals and native language interference with refined theoretical models to specify the links between perception and production in second language acquisition.

Apples and Oranges: Developmental Discontinuities in Spoken-Language Processing?

Much research focuses on speech processing in infancy, sometimes generating the impression that speech-sound categories do not develop further. Yet other studies suggest substantial plasticity throughout mid-childhood. Differences between infant versus child and adult experimental methods currently obscure how language processing changes across childhood, calling for approaches that span development.

Individual differences in perceptual adaptability of foreign sound categories.

Listeners possess a remarkable ability to adapt to acoustic variability in the realization of speech sound categories (e.g., different accents). The current work tests whether non-native listeners adapt their use of acoustic cues in phonetic categorization when they are confronted with changes in the distribution of cues in the input, as native listeners do, and examines to what extent these adaptation patterns are influenced by individual cue-weighting strategies. In line with previous work, native English listeners, who use voice onset time (VOT) as a primary cue to the stop voicing contrast (e.g., 'pa' vs. 'ba'), adjusted their use of f0 (a secondary cue to the contrast) when confronted with a noncanonical "accent" in which the two cues gave conflicting information about category membership. Native Korean listeners' adaptation strategies, while variable, were predictable based on their initial cue weighting strategies. In particular, listeners who used f0 as the primary cue to category membership adjusted their use of VOT (their secondary cue) in response to the noncanonical accent, mirroring the native pattern of "downweighting" a secondary cue. Results suggest that non-native listeners show native-like sensitivity to distributional information in the input and use this information to adjust categorization, just as native listeners do, with the specific trajectory of category adaptation governed by initial cue-weighting strategies.

Context-dependent categorical perception in a songbird

The division of continuously variable acoustic signals into discrete perceptual categories is a fundamental feature of human speech. Other animals have been found to categorize speech sounds much the same as humans do, although little is known of the role of categorical perception by animals in their own natural communication systems. A hallmark of human categorical perception of speech is that linguistic context affects both how speech sounds are categorized into phonemes, and how different versions of phonemes are produced. I first review earlier findings showing that a species of songbird, the swamp sparrow, categorically perceives the notes that constitute its learned songs and that individual neurons in the bird’s brain show categorical responses that map onto its behavioral response. I then present more recent data, using both discrimination and labeling tests, that show how swamp sparrows perceive categorical boundaries differently depending on context. These results demonstrate that there is a more complex relationship between underlying categorical representations and surface forms in the perception of birdsong. To our knowledge, this work suggests for the first time that this higher-order characteristic of human phonology is also found in a nonhuman communication system.

Complex linguistic rules modulate early auditory brain responses

During speech perception, listeners compensate for phonological rules of their language. For instance, English place assimilation causes green boat to be typically pronounced as greem boat; English listeners, however, perceptually compensate for this rule and retrieve the intended sound (n). Previous research using EEG has focused on rules with clear phonetic underpinnings, showing that perceptual compensation occurs at an early stage of speech perception. We tested whether this early mechanism also accounts for the compensation for more complex rules. We examined compensation for French voicing assimilation, a rule with abstract phonological restrictions on the contexts in which it applies. Our results reveal that perceptual compensation for this rule by French listeners modulates an early ERP component. This is evidence that early stages of speech sound categorization are sensitive to complex phonological rules of the native language.

Pattern-Induced Covert Category Learning in Songbirds

Language is uniquely human, but its acquisition may involve cognitive capacities shared with other species. During development, language experience alters speech sound (phoneme) categorization. Newborn infants distinguish the phonemes in all languages but by 10 months show adult-like greater sensitivity to native language phonemic contrasts than non-native contrasts. Distributional theories account for phonetic learning by positing that infants infer category boundaries from modal distributions of speech sounds along acoustic continua. For example, tokens of the sounds /b/ and /p/ cluster around different mean voice onset times. To disambiguate overlapping distributions, contextual theories propose that phonetic category learning is informed by higher-level patterns (e.g., words) in which phonemes normally occur. For example, the vowel sounds /Ι/ and /e/ can occupy similar perceptual spaces but can be distinguished in the context of "with" and "well." Both distributional and contextual cues appear to function in speech acquisition. Non-human species also benefit from distributional cues for category learning, but whether category learning benefits from contextual information in non-human animals is unknown. The use of higher-level patterns to guide lower-level category learning may reflect uniquely human capacities tied to language acquisition or more general learning abilities reflecting shared neurobiological mechanisms. Using songbirds, European starlings, we show that higher-level pattern learning covertly enhances categorization of the natural communication sounds. This observation mirrors the support for contextual theories of phonemic category learning in humans and demonstrates a general form of learning not unique to humans or language.

Enhanced procedural learning of speech sound categories in a genetic variant of FOXP2.

A mutation of the forkhead box protein P2 (FOXP2) gene is associated with severe deficits in human speech and language acquisition. In rodents, the humanized form of FOXP2 promotes faster switching from declarative to procedural learning strategies when the two learning systems compete. Here, we examined a polymorphism of FOXP2 (rs6980093) in humans (214 adults; 111 females) for associations with non-native speech category learning success. Neurocomputational modeling results showed that individuals with the GG genotype shifted faster to procedural learning strategies, which are optimal for the task. These findings support an adaptive role for the FOXP2 gene in modulating the function of neural learning systems that have a direct bearing on human speech category learning.

Infants’ Discrimination of Consonants: Interplay Between Word Position and Acoustic Saliency

ABSTRACTResearch has shown that young infants use contrasting acoustic information to distinguish consonants. This has been used to argue that by 12 months, infants have homed in on their native language sound categories. However, this ability seems to be positionally constrained, with contrasts at the beginning of words (onsets) discriminated earlier. This study explores whether English-learning 12- and 20-month-olds discriminate coda consonants in word-final and word-medial positions. The 12-month-old group successfully discriminated place of articulation contrasts for voiced stops in word-final position, though not voiceless stops in either position, while the older infants discriminated place of articulation contrasts for both voiced and voiceless stops in both positions. This indicates that voiced stops may be more acoustically salient than voiceless, and that position influences discrimination. Our findings support the claim that infants build speech sound categories starting with more salient contrasts in strong positions, which expand to other positions over the course of development.

Determinants of Variation in Rapid Temporal Processing Ability: How do Behaviour, Function, and Structure Relate?

Event Abstract Back to Event Determinants of Variation in Rapid Temporal Processing Ability: How do Behaviour, Function, and Structure Relate? Jesse Bourke1* and Juanita Todd1 1 University of Newcastle, School of Psychology, Australia Abstract Effective processing of rapid temporal cues in sound is essential for accurate perception of auditory stimuli, particularly for speech (Zatorre & Gandour, 2008). Poor rapid temporal processing (RTP) ability has been widely linked with disorders of speech and language processing (e.g., Cardy, Flagg, Roberts, Brian, & Roberts, 2005; Farmer & Klein, 1995). Todd, Finch, Smith, Budd, and Schall (2011) demonstrated that pre-attentive psychophysiological processing of RTP cues typically produces a right ear-advantage, depending on the individual’s behavioural ability to consciously discriminate RTP cues. A mismatch negativity (MMN) paradigm and gap detection threshold task (GDT) was used to measure behaviour and function respectively. Although neuroanatomical substrates of these effects have not yet been established, leftward structural lateralisations of the planum temporale (PT) may be a potential determinant (Elmer, Hänggi, Meyer, & Jäncke, 2013; Griffiths & Warren, 2002). In the present study we extended Todd et al.’s study by comparing behavioural and functional indices of RTP, with measures of the PT using structural MRI. Preliminary results have shown significant correlation of left-hemisphere PT surface area with RTP ability for stimuli presented to the right ear. Furthermore, more pronounced leftward laterality of the PT was correlated with larger MMN elicited to gap-deviants presented to the right-ear. Behavioural and structural measures were shown to be significant covariates for MMN at these frontal sites, but not for an observed polarity inversion at the mastoids. Overall, these findings affirm that the PT are a neuroanatomical substrate of the relationship between behavioural and functional RTP. References Anderson, S., Chandrasekaran, B., Yi, H. G., & Kraus, N. (2010). Cortical-evoked potentials reflect speech-in-noise perception in children. Eur J Neurosci, 32(8), 1407-1413. doi:10.1111/j.1460-9568.2010.07409.x Dimitrijevic, A., Pratt, H., & Starr, A. (2013). Auditory cortical activity in normal hearing subjects to consonant vowels presented in quiet and in noise. Clin Neurophysiol, 124(6), 1204-1215. doi:10.1016/j.clinph.2012.11.014 Elmer, S., Hänggi, J., Meyer, M., & Jäncke, L. (2013). Increased cortical surface area of the left planum temporale in musicians facilitates the categorization of phonetic and temporal speech sounds. Cortex, 49(10), 2812-2821. doi:10.1016/j.cortex.2013.03.007 Griffiths, T. D., & Warren, J. D. (2002). The planum temporale as a computational hub. Trends in Neurosciences, 25(7), 348-353. Hautus, M. J., & Johnson, B. W. (2005). Object-related brain potentials associated with the perceptual segregation of a dichotically embedded pitch. The Journal of the Acoustical Society of America, 117(1), 275. doi:10.1121/1.1828499 Todd, J., Finch, B., Smith, E., Budd, T. W., & Schall, U. (2011). Temporal processing ability is related to ear-asymmetry for detecting time cues in sound: a mismatch negativity (MMN) study. Neuropsychologia, 49(1), 69-82. doi:10.1016/j.neuropsychologia.2010.10.029 Zatorre, R. J., & Gandour, J. T. (2008). Neural specializations for speech and pitch: moving beyond the dichotomies. Philos Trans R Soc Lond B Biol Sci, 363(1493), 1087-1104. doi:10.1098/rstb.2007.2161 Keywords: gap detection, mismatch negativity, planum temporale, dichotic listening, asymmetry Conference: ASP2015 - 25th Annual Conference of the Australasian Society for Psychophysiology, Sydney, Australia, 2 Dec - 4 Dec, 2015. Presentation Type: Oral Presentation Topic: Psychophysiology Citation: Bourke J and Todd J (2015). Determinants of Variation in Rapid Temporal Processing Ability: How do Behaviour, Function, and Structure Relate?. Conference Abstract: ASP2015 - 25th Annual Conference of the Australasian Society for Psychophysiology. doi: 10.3389/conf.fnhum.2015.219.00008 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 24 Oct 2015; Published Online: 30 Nov 2015. * Correspondence: Mr. Jesse Bourke, University of Newcastle, School of Psychology, Newcastle, Australia, jesse.d.bourke@newcastle.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Jesse Bourke Juanita Todd Google Jesse Bourke Juanita Todd Google Scholar Jesse Bourke Juanita Todd PubMed Jesse Bourke Juanita Todd Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

The perception of the French /s/-/ʃ/ contrast in early Creole-French bilinguals.

One particularity of the Mauritian Creole language is that there is no contrastive distinction between the consonants /s/ and /ʃ/, which are both pronounced /s/ in Creole. In this study, we examined the identification performance of the /s/-/ʃ/ contrast by Mauritian Creole-French bilinguals who have been exposed to French before 7 years of age, and who have been raised in a highly Creole-French bilingual society. The results showed that most of our bilingual participants identify the /s/ and /ʃ/ consonants like native French speakers. It also appeared that the way in which the two consonants are categorized can be manipulated by introducing subtle changes in the information these participants were given about the identity of the speaker that produced the stimuli. Our results are in accordance with recent studies showing native-like performance in bilinguals on a categorization task and, importantly, extend these findings to speakers of a Creole language. In addition, these results show that speech sound categorization can be influenced by information about the speaker's social identity and thus argue for models that postulate rich speech sound representations.

Music and Language Expertise Influence the Categorization of Speech and Musical Sounds: Behavioral and Electrophysiological Measurements

In this study, we used high-density EEG to evaluate whether speech and music expertise has an influence on the categorization of expertise-related and unrelated sounds. With this purpose in mind, we compared the categorization of speech, music, and neutral sounds between professional musicians, simultaneous interpreters (SIs), and controls in response to morphed speech-noise, music-noise, and speech-music continua. Our hypothesis was that music and language expertise will strengthen the memory representations of prototypical sounds, which act as a perceptual magnet for morphed variants. This means that the prototype would "attract" variants. This so-called magnet effect should be manifested by an increased assignment of morphed items to the trained category, by a reduced maximal slope of the psychometric function, as well as by differential event-related brain responses reflecting memory comparison processes (i.e., N400 and P600 responses). As a main result, we provide first evidence for a domain-specific behavioral bias of musicians and SIs toward the trained categories, namely music and speech. In addition, SIs showed a bias toward musical items, indicating that interpreting training has a generic influence on the cognitive representation of spectrotemporal signals with similar acoustic properties to speech sounds. Notably, EEG measurements revealed clear distinct N400 and P600 responses to both prototypical and ambiguous items between the three groups at anterior, central, and posterior scalp sites. These differential N400 and P600 responses represent synchronous activity occurring across widely distributed brain networks, and indicate a dynamical recruitment of memory processes that vary as a function of training and expertise.

Study of the effects of vocal tract constriction on glottal vibration.

Characteristics of glottal vibration are affected by the obstruction to the flow of air through the vocal tract system. The obstruction to the airflow is determined by the nature, location, and extent of constriction in the vocal tract during production of voiced sounds. The effects of constriction on glottal vibration are examined for six different categories of speech sounds having varying degree of constriction. The effects are examined in terms of source and system features derived from the speech and electroglottograph signals. It is observed that a high degree of constriction causing obstruction to the flow of air results in large changes in these features, relative to the adjacent steady vowel regions, as in the case of apical trill and alveolar fricative sounds. These changes are insignificant when the obstruction to the airflow is less, as in the case of velar fricative and lateral approximant sounds. There are no changes in the excitation features when there is a free flow of air along the auxiliary tract, despite constriction in the vocal tract, as in the case of nasals. These studies show that effects of constriction can indeed be observed in the features of glottal vibration as well as vocal tract resonances.

Perceptual weighting strategies of children with cochlear implants and normal hearing

PurposeThis study compared perceptual weighting strategies of children with cochlear implants (CIs) and children with normal hearing (NH), and asked if strategies are explained solely by degraded spectral representations, or if diminished language experience accounts for some of the effect. Relationships between weighting strategies and other language skills were examined. MethodOne hundred 8-year-olds (49 with NH and 51 with CIs) were tested on four measures: (1) labeling of cop–cob and sa–sha stimuli; (2) discrimination of the acoustic cues to the cop–cob decision; (3) phonemic awareness; and (4) word recognition. ResultsNo differences in weighting of cues to the cop–cob decision were observed between children with CIs and NH, suggesting that language experience was sufficient for the children with CIs. Differences in weighting of cues to the sa–sha decision were found, but were not entirely explained by auditory sensitivity. Weighting strategies were related to phonemic awareness and word recognition. ConclusionsMore salient cues facilitate stronger weighting of those cues. Nonetheless, individuals differ in how salient cues need to be to capture perceptual attention. Familiarity with stimuli also affects how reliably children attend to acoustic cues. Training should help children with CIs learn to categorize speech sounds with less-salient cues.Learning outcomes: After reading this article, the learner should be able to: (1) recognize methods and motivations for studying perceptual weighting strategies in speech perception; (2) explain how signal quality and language experience affect the development of weighting strategies for children with cochlear implants and children with normal hearing; and (3) summarize the importance of perceptual weighting strategies for other aspects of language functioning.

Plasticity in the Human Speech Motor System Drives Changes in Speech Perception

Recent studies of human speech motor learning suggest that learning is accompanied by changes in auditory perception. But what drives the perceptual change? Is it a consequence of changes in the motor system? Or is it a result of sensory inflow during learning? Here, subjects participated in a speech motor-learning task involving adaptation to altered auditory feedback and they were subsequently tested for perceptual change. In two separate experiments, involving two different auditory perceptual continua, we show that changes in the speech motor system that accompany learning drive changes in auditory speech perception. Specifically, we obtained changes in speech perception when adaptation to altered auditory feedback led to speech production that fell into the phonetic range of the speech perceptual tests. However, a similar change in perception was not observed when the auditory feedback that subjects' received during learning fell into the phonetic range of the perceptual tests. This indicates that the central motor outflow associated with vocal sensorimotor adaptation drives changes to the perceptual classification of speech sounds.

Respostas evocadas de incongruência a categorias na percepção da fala.

Speech perception involves categorization operations in which acoustic events that compose the speech stream are grouped into equivalence classes, i. e., categories whose members are treated by speakers as functionally equivalent. Several lines of evidence indicate effects of speech sound categories on perception. In this context, measures of neural activity related to perceptual processing at the level of the cerebral cortex are of great relevance. Psychophysiological studies show that the Mismatch Negativity (MMN) component of the auditory evoked responses, which has been regarded as an index of auditory sensory memoryand discrimination, is sensitive not only to the physical attributes of the speech sounds but also to the way those sounds are categorized by the speakers of a language. The present work offers a critical retrospective review of the use of the MMN response in research on speech sound categorization and an appreciation of its contributions to the comprehension of the perceptual aspects of speech communication.