Classes Of Speech Sounds Research Articles

Native language experience influences the topography of the mismatch negativity to speech.

The ability to learn second language speech sound categories declines during development. We examined this phenomenon by studying the mismatch negativity (MMN) to the /r/ – /l/ distinction in native English speakers and learners of English as a second language who are native speakers of Japanese. Previous studies have suggested that the MMN is remarkably plastic when evaluated as a waveform at a central electrode. We replicated this finding: analyses of the MMN at a typical electrode location (Fz) revealed only small, non-significant differences between groups, despite large behavioral differences in the ability to discriminate these sounds from one another. Topographic analyses, however, revealed reliable differences in lateralization of the MMN, such that native English speakers’ responses were left-lateralized relative to native Japanese speakers’ responses.

Mandarin Vowels Revisited: Evidence from Electromagnetic Articulography

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Auditory plasticity and speech motor learning.

Is plasticity in sensory and motor systems linked? Here, in the context of speech motor learning and perception, we test the idea sensory function is modified by motor learning and, in particular, that speech motor learning affects a speaker's auditory map. We assessed speech motor learning by using a robotic device that displaced the jaw and selectively altered somatosensory feedback during speech. We found that with practice speakers progressively corrected for the mechanical perturbation and after motor learning they also showed systematic changes in their perceptual classification of speech sounds. The perceptual shift was tied to motor learning. Individuals that displayed greater amounts of learning also showed greater perceptual change. Perceptual change was not observed in control subjects that produced the same movements, but in the absence of a force field, nor in subjects that experienced the force field but failed to adapt to the mechanical load. The perceptual effects observed here indicate the involvement of the somatosensory system in the neural processing of speech sounds and suggest that speech motor learning results in changes to auditory perceptual function.

Implicit and explicit categorization of speech sounds – dissociating behavioural and neurophysiological data

During speech perception, sound is mapped onto abstract phonological categories. Assimilation of place or manner of articulation in connected speech challenges this categorization. Does assimilation result in categorizations that need to be corrected later on, or does the system get it right immediately? Participants were presented with isolated nasals (/m/ labial, /n/ alveolar, and /n'/ assimilated towards labial place of articulation), extracted from naturally produced German utterances. Behavioural two-alternative forced-choice tasks showed that participants could correctly categorize the /n/s and /m/s. The assimilated nasals were predominantly categorized as /m/, indicative of a perceived change in place. A pitch variation additively influenced the categorizations. Using magnetoencephalography (MEG), we analysed the N100m elicited by the same stimuli without a categorization task. In sharp contrast to the behavioural data, this early, automatic brain response ignored the assimilation in the surface form and reflected the underlying category. As shown by distributed source modelling, phonemic differences were processed exclusively left-laterally (temporally and parietally), whereas the pitch variation was processed in temporal regions bilaterally. In conclusion, explicit categorization draws attention to the surface form - to the changed place and acoustic information. The N100m reflects automatic categorization, which exploits any hint of an underlying feature.

Automatic auditory discrimination of vowels in simultaneous bilingual and monolingual speakers as measured by the mismatch negativity (MMN).

MMN responses reflect whether language users have developed long‐term memory traces in response to phonemes and whether they are able to perceive small acoustic changes within speech sound categories. Subtle acoustic changes within phonemes are often irrelevant to monolingual perceivers, but can be crucial for bilingual perceivers if the acoustic change differentiates the phonemes of their two languages. In the present study, we investigated whether bilinguals are sensitive to such acoustic changes. We recorded MMN responses from monolingual (English, French) and simultaneous bilingual (English/French) adults using an auditory oddball paradigm in response to four vowels: English [u], French [u], French [y], and an acoustically‐distinct (control) [y]. In line with previous findings, monolinguals were more sensitive to the phonemic status of the vowels than to the acoustic properties differentiating the sounds. Bilingual speakers revealed a different pattern; they demonstrated overall slower discrimination responses to all sounds, but showed almost equal sensitivity to phonemic and phonetic/acoustic differences. The results suggest that bilingual speakers exhibit a more flexible but less uniquely‐specified perceptual pattern compared to monolingual speakers.

Native language experience influences the perceived similarity of second language vowel categories.

Most studies of L2 speech perception seek to characterize—at least implicitly—how the similarity among L2 speech sound categories is shaped by L1 experience. Intercategory similarity for native language speakers is rarely considered, however. Here, we derive two indices of graded intercategory similarity for a front vowel series (pin, pen, and pan): One from an off‐line perceptual similarity judgment task and a second from online measures of arm‐movement trajectories in a word recognition task. Both tasks revealed graded effects of intercategory similarity, but the similarity spaces differed between language groups. Both groups perceived /ae/ and /E/ to be most similar, but the native Italian speakers perceived /I/ to be equally similar to /E/ and /ae/, whereas English speakers perceived the /I/ and /E/ to be more similar than /I/ and /ae/. The Italian speakers’ performance in both tasks suggests a similarity space that is dominated by dimensions that are contrastive for /I/ with respect to the other vowels. This may reflect a compensatory strategy for L2 vowel perception that may derive from experience with the distributional properties of their native vowels.

How are speech sound categories acquired in bilingual first language acquisition?

For bilingual infants, phonetic categories of the two languages develop interdependently. This is supported by the differences in time course and trajectory of development of phonetic perception between Spanish-Catalan bilingual and monolingual infants (Bosch and Sebastián-Gallés, 2003a, 2003b, 2005; Sebastián-Gallés and Bosch, in press). Bosch and Sebastián-Gallés argue that for similar phones, at least initially, infants track statistical regularities across the two languages. This results in a temporary inability of bilingual infants to discriminate acoustically similar phonemes. Research on French-English bilingual infants shows a different pattern. There is evidence that French-English bilingual infants may not differ from their monolingual peers in discrimination of phonetic contrasts (Burns et al., 2007; Sundara et al., 2008). In this talk, data will be presented from Spanish-English bilingual infants to evaluate how development of phonetic perception is affected by (a) frequency of phones and (b) the rhythmic (dis)similarity of the two languages to which bilinguals are exposed.

Two languages in one brain - slower phonological processing

Event Abstract Back to Event Two languages in one brain - slower phonological processing Maija Peltola1, 2*, H. Tamminen1, 2, H. Lehtola1, 2, T. Kujala3 and R. Näätänen3, 4, 5 1 Department of Phonetics, University of Turku, Finland 2 Centre for Cognitive Neuroscience, University of Turku, Finland 3 Department of Psychology, University of Helsinki, Finland 4 Department of Psychology, University of Tartu, Estonia 5 Center of Functionally Integrative Neuroscience, University of Aarhus, Denmark Phoneme perception is known to be language-specific so that mother tongue contrasts are discriminated easily and preattentively on the basis of long term memory traces. Behavioral and psychophysiological studies have established that discrimination sensitivity is at its peak at the native language phoneme boundaries and lowest near the native speech sound category prototypes. Bilinguals have a large amount of phonological categories that need to be kept apart. The aim of the present study was to determine whether monolinguals and bilinguals perceive speech sounds similarly or whether the two systems in bilinguals interact in a manner that one native language may be affected by the other. Two groups participated in the experiment: Group 1 consisted of 10 native speakers of Finnish and Group 2 of 12 balanced Finnish-Swedish bilinguals. Both groups were tested by the same Finnish speaking researcher. The stimuli were individually chosen on the basis of a prior identification experiment, which covered the rounded closed vowel continuum ranging form /y/ to /u/. The stimulus pair crossed the Finnish phoneme boundary /y/-/u/, but it was within the Swedish fronted /u/ vowel. We analyzed both the MMN peak latency (150-300 ms) and amplitude (two consecutive time windows 180-230 ms and 230-280 ms). The latency analysis revealed a significant effect of group resulting from a longer MMN latency in the bilingual than monolingual group. Consistently, the amplitude analysis revealed a significant interaction between the time window and group, again showing the lateness of the bilingual response. In addition, the amplitude analysis showed a group main effect suggesting a reduced MMN amplitude in the bilingual group. The groups differed significantly in their responses in the fist time window, where the monolinguals’ response was larger, but no group differences were found in the second time window. These results suggest slower preattentive processing in bilinguals than in monolinguals. This might be due to the more extensive intertwined phonological system from which items are accessed more slowly. The result showing a reduced MMN amplitude in bilinguals may be explained by interference from the other system, where the same contrast is non-phonemic, thus resulting in a small response. Conference: MMN 09 Fifth Conference on Mismatch Negativity (MMN) and its Clinical and Scientific Applications, Budapest, Hungary, 4 Apr - 7 Apr, 2009. Presentation Type: Poster Presentation Topic: Poster Presentations Citation: Peltola M, Tamminen H, Lehtola H, Kujala T and Näätänen R (2009). Two languages in one brain - slower phonological processing. Conference Abstract: MMN 09 Fifth Conference on Mismatch Negativity (MMN) and its Clinical and Scientific Applications. doi: 10.3389/conf.neuro.09.2009.05.149 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: 26 Mar 2009; Published Online: 26 Mar 2009. * Correspondence: Maija Peltola, Department of Phonetics, University of Turku, Turku, Finland, maipie@utu.fi 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 Maija Peltola H. Tamminen H. Lehtola T. Kujala R. Näätänen Google Maija Peltola H. Tamminen H. Lehtola T. Kujala R. Näätänen Google Scholar Maija Peltola H. Tamminen H. Lehtola T. Kujala R. Näätänen PubMed Maija Peltola H. Tamminen H. Lehtola T. Kujala R. Näätänen 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.

Testing the double phonemic boundary in bilinguals

It is widely known that language influences the way speech sounds are categorized. However, categorization of speech sounds by bilinguals is not well understood. There is evidence that bilinguals have different category boundaries than monolinguals, and there is evidence suggesting that bilinguals’ phonemic boundaries can shift with language context. This phenomenon has been referred as the double phonemic boundary. In this investigation, the double phonemic boundary is tested in Spanish-English bilinguals ( N = 18) and English monolinguals ( N = 16). Participants were asked to categorize speech stimuli from a continuum ranging from /ga/ to /ka/ in two language contexts. The results showed phonemic boundary shifts in bilinguals and monolinguals which did not differ across language contexts. However, the magnitude of the phoneme boundary shift was significantly correlated with the level of confidence in using English and Spanish (reading, writing, speaking, and comprehension) for bilinguals, but not for monolinguals. The challenges of testing the double phonemic boundary are discussed, along with the limitations of the methodology used in this study.

Retuning speech sound categories: An eyetracking study.

Speech categories are defined by multiple probabilistic acoustic cues. Fundamental frequency (F0) and voice onset time (VOT) are correlated in the English stop voicing contrast, for example. However, such correlations are often imperfect—especially in cases of non‐native or disordered speech. The present experiments investigate listeners’ ability to adjust perceptual cue weighting in online perception in response to changes in the cue correlations experienced across time. Native‐English listeners heard minimal‐pair words beginning with stop consonants varying along a VOT series. The F0 of the words was gradually shifted over the course of the experiment from the canonical English correlation (higher F0 for voiceless stops) to the opposite pattern (lower F0 for voiceless stops). Categorization was assessed via explicit responses while eye gaze data were simultaneously recorded using the visual world paradigm. Both data types revealed that the influence of F0 on voicing categorization changed in response to changes in F0/VOT correlation. Some listeners use of F0 reversed such that higher F0 led to more voiced responses; other listeners discontinued use of F0 in voicing categorization. These patterns suggest that listeners are continually monitoring the input for regularity and retuning acoustic cue use in an online manner to accommodate these regularities.

The roots of the early vocabulary in infants' learning from speech.

Psychologists have known for over 20 years that infants begin learning their language's speech sound categories during the first 12 months of life. This fact has dominated researchers' thinking about how language acquisition begins, although the relevance of this learning to the child's progress in language acquisition has never been clear. Recently, views of the role of infancy in language acquisition have begun to change, with a new focus on the development of the vocabulary. Infants' learning of speech sound categories, and infants' abilities to extract regularities in the speech stream, allow learning of the auditory forms of many words. These word forms then become the foundation of the early vocabulary, support children's learning of the language's phonological system, and contribute to the discovery of grammar.

Evaluation of an Artificial Speech Bandwidth Extension Method in Three Languages

Quality and intelligibility of narrowband telephone speech can be improved by artificial bandwidth extension (ABE), which extends the speech bandwidth using only information available in the narrowband speech signal. This paper reports a three-language evaluation of an ABE method that has recently been launched in several of Nokia's mobile telephone models. The method extends the speech bandwidth to frequencies above the telephone band by first utilizing spectral folding and then modifying the magnitude spectrum of the extension band with spline curves. The performance of the method was evaluated by formal listening tests in American English, Russian, and Mandarin Chinese. The results of the listening tests indicate that ABE processing improved the subjective quality of coded narrowband speech in all these languages. Differences between bandwidth-extended American English test sentences and their original wideband counterparts were also evaluated using both an objective distance measure that simulates the characteristics of human hearing and a conventional spectral distortion measure. The average objective error was calculated for different categories of speech sounds. The error was found to be smallest in nasals and semivowels and largest in fricative sounds.

Native language governs interpretation of salient speech sound differences at 18 months.

One of the first steps infants take in learning their native language is to discover its set of speech-sound categories. This early development is shown when infants begin to lose the ability to differentiate some of the speech sounds their language does not use, while retaining or improving discrimination of language-relevant sounds. However, this aspect of early phonological tuning is not sufficient for language learning. Children must also discover which of the phonetic cues that are used in their language serve to signal lexical distinctions. Phonetic variation that is readily discriminable to all children may indicate two different words in one language but only one word in another. Here, we provide evidence that the language background of 1.5-year-olds affects their interpretation of phonetic variation in word learning, and we show that young children interpret salient phonetic variation in language-specific ways. Three experiments with a total of 104 children compared Dutch- and English-learning 18-month-olds' responses to novel words varying in vowel duration or vowel quality. Dutch learners interpreted vowel duration as lexically contrastive, but English learners did not, in keeping with properties of Dutch and English. Both groups performed equivalently when differentiating words varying in vowel quality. Thus, at one and a half years, children's phonological knowledge already guides their interpretation of salient phonetic variation. We argue that early phonological learning is not just a matter of maintaining the ability to distinguish language-relevant phonetic cues. Learning also requires phonological interpretation at appropriate levels of linguistic analysis.

Two-month-old infants at risk for dyslexia do not discriminate /bAk/ from /dAk/: A brain-mapping study

Dyslexics have problems with categorization of speech sounds, in particular when rapid temporal processing is involved such as in formant transitions of stop-consonants. Infants are already sensitive to such auditory features, but here we show that precursors of impaired categorization are already present in the brain responses of two-month-old infants at familial risk for dyslexia. Natural speech stimuli (/bAk/ and /dAk/), at either side of the phoneme boundary, induced multiple mismatch responses in control infants under pre-attentive and pre-cognitive conditions. Infants at-risk showed an attenuated early mismatch response and an absent late one, in addition to diminished cortical activity in the left hemisphere. These results are consistent with a temporal processing deficit in the infants at risk and may point to an early precursor of the disorder.

How human infants deal with symbol grounding

Taking a distributed view of language, this paper naturalizes symbol grounding. Learning to talk is traced to — not categorizing speech sounds — but events that shape the rise of human-style autonomy. On the extended symbol hypothesis, this happens as babies integrate micro-activity with slow and deliberate adult action. As they discover social norms, intrinsic motive formation enables them to reshape co-action. Because infants link affect to contingencies, dyads develop norm-referenced routines. Over time, infant doings become analysis amenable. The caregiver of a nine-month-old may, for example, prompt the baby to fetch objects. Once she concludes that the baby uses ‘words’ to understand what she says, the infant can use this belief in orienting to more abstract contingencies. New cognitive powers will develop as the baby learns to act in ways that are consistent with a caregiver’s false belief that her baby uses ‘words.’

Determinants of auditory cue weighting and selective attention

The categorization of speech sounds into phonetic units has been characterized as involving the differential weighting of perceptual cues. Cue weighting has been often explicitly or implicitly associated with the construct of selective attention. We will present data from speech and non‐speech categorization studies that attempt to illuminate the factors that influence relative weighting of perceptual dimensions. Of particular interest is the role of variability across the different auditory dimensions. The results of these experiments will be related to work on cue weighting in other psychophysical tasks and the usefulness of the attention construct will be explored. [Work supported by NSF BCS0345773].

Effects of irrelevant speech and traffic noise on speech perception and cognitive performance in elementary school children

The effects of background noise of moderate intensity on short-term storage and processing of verbal information were analyzed in 6 to 8 year old children. In line with adult studies on "irrelevant sound effect" (ISE), serial recall of visually presented digits was severely disrupted by background speech that the children did not understand. Train noises of equal Intensity however, had no effect. Similar results were demonstrated with tasks requiring storage and processing of heard information. Memory for nonwords, execution of oral instructions and categorizing speech sounds were significantly disrupted by irrelevant speech. The affected functions play a fundamental role in the acquisition of spoken and written language. Implications concerning current models of the ISE and the acoustic conditions in schools and kindergardens are discussed.

Perception and production of long and short vowels in Japanese by children

Studies have shown that acquisition of reading depends on such phonological processes as verbal short‐term memory and temporal processing of speech. An inability to encode phonological representations orthographically may cause reading disabilities, such as dyslexia. Categorical perception is known to be closely associated with phonological encoding. Thus, studies examining the temporal processing of speech sound categorization may be useful in differential diagnoses of reading development and disabilities. The first study examines the perception of long and short Japanese vowels by a group of seven normal six‐year‐old children and two with delayed phonological development. Subjects were asked to identify vowel length in sets of words. The first vowel in each stimulus word was made to vary with respect to length. Perception by normal and delayed children differed in ways similar to what had been reported in previous English studies. In the second study, the relation between perception and reading of long/short vowels was examined by a group of 125 children ages 4 to 8. Similar settings were used for the second experiment. The results showed that (1) a large developmental change of perception was observed in ages 6–8 and (2) a positive correlation was obtained between perception and reading tasks.

Infant-directed speech supports phonetic category learning in English and Japanese

Across the first year of life, infants show decreased sensitivity to phonetic differences not used in the native language [Werker, J. F., & Tees, R. C. (1984). Cross-language speech perception: evidence for perceptual reorganization during the first year of life. Infant Behaviour and Development, 7, 49–63]. In an artificial language learning manipulation, Maye, Werker, and Gerken [Maye, J., Werker, J. F., & Gerken, L. (2002). Infant sensitivity to distributional information can affect phonetic discrimination. Cognition, 82(3), B101–B111] found that infants change their speech sound categories as a function of the distributional properties of the input. For such a distributional learning mechanism to be functional, however, it is essential that the input speech contain distributional cues to support such perceptual learning. To test this, we recorded Japanese and English mothers teaching words to their infants. Acoustic analyses revealed language-specific differences in the distributions of the cues used by mothers (or cues present in the input) to distinguish the vowels. The robust availability of these cues in maternal speech adds support to the hypothesis that distributional learning is an important mechanism whereby infants establish native language phonetic categories.

Cue weighting in auditory categorization: Implications for first and second language acquisition

The ability to integrate and weight information across dimensions is central to perception and is particularly important for speech categorization. The present experiments investigate cue weighting by training participants to categorize sounds drawn from a two-dimensional acoustic space defined by the center frequency (CF) and modulation frequency (MF) of frequency-modulated sine waves. These dimensions were psychophysically matched to be equally discriminable and, in the first experiment, were equally informative for accurate categorization. Nevertheless, listeners' category responses reflected a bias for use of CF. This bias remained even when the informativeness of CF was decreased by shifting distributions to create more overlap in CF. A reversal of weighting (MF over CF) was obtained when distribution variance was increased for CF. These results demonstrate that even when equally informative and discriminable, acoustic cues are not necessarily equally weighted in categorization; listeners exhibit biases when integrating multiple acoustic dimensions. Moreover, changes in weighting strategies can be affected by changes in input distribution parameters. This methodology provides potential insights into acquisition of speech sound categories, particularly second language categories. One implication is that ineffective cue weighting strategies for phonetic categories may be alleviated by manipulating variance of uninformative dimensions in training stimuli.