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Mitchell Steinschneider - One of the best experts on this subject based on the ideXlab platform.

  • intracortical responses in human and monkey primary auditory cortex support a temporal processing mechanism for encoding of the Voice Onset Time phonetic parameter
    Cerebral Cortex, 2004
    Co-Authors: Mitchell Steinschneider, Igor O Volkov, Joseph C Arezzo, Yonatan I Fishman, Matthew A Howard
    Abstract:

    This study tests the hypothesis that temporal response patterns in primary auditory cortex are potentially relevant for Voice Onset Time (VOT) encoding in two related experiments. The first experiment investigates whether temporal responses reflecting VOT are modulated in a way that can account for boundary shifts that occur with changes in first formant (F1) frequency, and by extension, consonant place of articulation. Evoked potentials recorded from Heschl’s gyrus in a patient undergoing epilepsy surgery evaluation are examined. Representation of VOT varies in a manner that reflects the spectral composition of the syllables and the underlying tonotopic organization. Activity patterns averaged across extended regions of Heschl’s gyrus parallel changes in the subject’s perceptual boundaries. The second experiment investigates whether the physiological boundary for detecting the sequence of two acoustic elements parallels the psychoacoustic result of ~20 ms. Population responses evoked by two-tone complexes with variable tone Onset Times (TOTs) in primary auditory cortex of the monkey are examined. Onset responses evoked by both the first and second tones are detected at a TOT separation as short as 20 ms. Overall, parallels between perceptual and physiological results support the relevance of a population-based temporal processing mechanism for VOT encoding.

  • representation of the Voice Onset Time vot speech parameter in population responses within primary auditory cortex of the awake monkey
    Journal of the Acoustical Society of America, 2003
    Co-Authors: Mitchell Steinschneider, Yonatan I Fishman, Joseph C Arezzo
    Abstract:

    Voice Onset Time (VOT) signifies the interval between consonant Onset and the start of rhythmic vocal-cord vibrations. Differential perception of consonants such as /d/ and /t/ is categorical in American English, with the boundary generally lying at a VOT of 20–40 ms. This study tests whether previously identified response patterns that differentially reflect VOT are maintained in large-scale population activity within primary auditory cortex (A1) of the awake monkey. Multiunit activity and current source density patterns evoked by the syllables /da/ and /ta/ with variable VOTs are examined. Neural representation is determined by the tonotopic organization. Differential response patterns are restricted to lower best-frequency regions. Response peaks Time-locked to both consonant and voicing Onsets are observed for syllables with a 40- and 60-ms VOT, whereas syllables with a 0- and 20-ms VOT evoke a single response Time-locked only to consonant Onset. Duration of aspiration noise is represented in higher best-frequency regions. Representation of VOT and aspiration noise in discrete tonotopic areas of A1 suggest that integration of these phonetic cues occurs in secondary areas of auditory cortex. Findings are consistent with the evolving concept that complex stimuli are encoded by synchronized activity in large-scale neuronal ensembles.

  • temporal encoding of the Voice Onset Time phonetic parameter by field potentials recorded directly from human auditory cortex
    Journal of Neurophysiology, 1999
    Co-Authors: Mitchell Steinschneider, Igor O Volkov, Charles P Garell, Matthew A Howard
    Abstract:

    Voice Onset Time (VOT) is an important parameter of speech that denotes the Time interval between consonant Onset and the Onset of low-frequency periodicity generated by rhythmic vocal cord vibrati...

  • physiologic correlates of the Voice Onset Time boundary in primary auditory cortex a1 of the awake monkey temporal response patterns
    Brain and Language, 1995
    Co-Authors: Mitchell Steinschneider, Charles E Schroeder, Joseph C Arezzo, Herbert G Vaughan
    Abstract:

    Behavioral studies in animals support the view that categorical, phonetic phenomena are based upon specific response properties of the auditory system. This study investigated physiologic responses reflecting the phonetic parameter of Voice Onset Time (VOT). We examined multiunit activity (MUA) in the primary auditory cortex (A1) of awake monkeys elicited by the consonant-vowel syllables /da/ and /ta/ that varied in VOT from 0 to 60 msec. Two temporal response patterns encode VOT. The first pattern contains responses Time-locked to stimulus Onset and to the Onset of voicing. In 10 of 17 electrode penetrations that display this pattern, MUA reflects the VOT perceptual boundary by containing a prominent response to voicing Onset only for /ta/ stimuli. The second pattern contains responses phase-locked to the periodic portion of the syllables. MUA exhibiting this temporal pattern does not display categorical-like properties. We conclude that specific temporal response patterns in A1 reflect the perceptual boundary for VOT and may represent a physiologic correlate for categorical perception of this phonetic parameter.

  • speech evoked activity in primary auditory cortex effects of Voice Onset Time
    Electroencephalography and Clinical Neurophysiology, 1994
    Co-Authors: Mitchell Steinschneider, Charles E Schroeder, Joseph C Arezzo, Herbert G Vaughan
    Abstract:

    Abstract Neural encoding of temporal speech features is a key component of acoustic and phonetic analyses. We examined the temporal encoding of the syllables /da/ and /ta/, which differ along the temporally based, phonetic parameter of Voice Onset Time (VOT), in primary auditory cortex (A1) of awake monkeys using concurrent multilaminar recordings of auditory evoked potentials (AEP), the derived current source density, and multiunit activity. A general sequence of A1 activation consisting of a lamina-specific profile of parallel and sequential excitatory and inhibitory processes is described. VOT is encoded in the temporal response patterns of phase-locked activity to the periodic speech segments and by “on” responses to stimulus and voicing Onset. A transformation occurs between responses in the thalamocortical (TC) fiber input and A1 cells. TC fibers are more likely to encode VOT with “on” responses to stimulus Onset followed by phase-locked responses during the Voiced segment, whereas A1 responses are more likely to exhibit transient responses both to stimulus and voicing Onset. Relevance to subcortical speech processing, the human AEP and speech psychoacoustics are discussed. A mechanism for categorical differentiation of Voiced and unVoiced consonants is proposed.

Matthew A Howard - One of the best experts on this subject based on the ideXlab platform.

Sheila E. Blumstein - One of the best experts on this subject based on the ideXlab platform.

  • An event-related fMRI investigation of Voice-Onset Time discrimination.
    NeuroImage, 2007
    Co-Authors: Emmette R. Hutchison, Sheila E. Blumstein, Emily B. Myers
    Abstract:

    Abstract The discrimination of Voice-Onset Time, an acoustic–phonetic cue to voicing in stop consonants, was investigated to explore the neural systems underlying the perception of a rapid temporal speech parameter. Pairs of synthetic stimuli taken from a [da] to [ta] continuum varying in Voice-Onset Time (VOT) were presented for discrimination judgments. Participants exhibited categorical perception, discriminating 15-ms and 30-ms between-category comparisons and failing to discriminate 15-ms within-category comparisons. Contrastive analysis with a tone discrimination task demonstrated left superior temporal gyrus activation in all three VOT conditions with recruitment of additional regions, particularly the right inferior frontal gyrus and middle frontal gyrus for the 15-ms between-category stimuli. Hemispheric differences using anatomically defined regions of interest showed two distinct patterns with anterior regions showing more activation in the right hemisphere relative to the left hemisphere and temporal regions demonstrating greater activation in the left hemisphere relative to the right hemisphere. Activation in the temporal regions appears to reflect initial acoustic–perceptual analysis of VOT. Greater activation in the right hemisphere anterior regions may reflect increased processing demands, suggesting involvement of the right hemisphere when the acoustic distance between the stimuli are reduced and when the discrimination judgment becomes more difficult.

  • the perception of Voice Onset Time an fmri investigation of phonetic category structure
    Journal of Cognitive Neuroscience, 2005
    Co-Authors: Sheila E. Blumstein, Emily B. Myers, Jesse Rissman
    Abstract:

    This study explored the neural systems underlying the perception of phonetic category structure by investigating the perception of a Voice Onset Time (VOT) continuum in a phonetic categorization task. Stimuli consisted of five synthetic speech stimuli which ranged in VOT from 0 msec ([da]) to 40 msec ([ta]). Results from 12 subjects showed that the neural system is sensitive to VOT differences of 10 msec and that details of phonetic category structure are retained throughout the phonetic processing stream. Both the left inferior frontal gyrus (IFG) and cingulate showed graded activation as a function of category membership with increasing activation as stimuli approached the phonetic category boundary. These results are consistent with the view that the left IFG is involved in phonetic decision processes, with the extent of activation influenced by increased resources devoted to resolving phonetic category membership and/or selecting between competing phonetic categories. Activation patterns in the cingulate suggest that it is sensitive to stimulus difficulty and resolving response conflict. In contrast, activation in the posterior left middle temporal gyrus and the left angular gyrus showed modulation of activation only to the "best fit" of the phonetic category, suggesting that these areas are involved in mapping sound structure to its phonetic representation. The superior temporal gyrus (STG) bilaterally showed weaker sensitivity to the differences in phonetic category structure, providing further evidence that the STG is involved in the early analysis of the sensory properties of speech.

  • effects of speaking rate on Voice Onset Time and vowel production some implications for perception studies
    Journal of Phonetics, 1998
    Co-Authors: R H Kessinger, Sheila E. Blumstein
    Abstract:

    Abstract An examination of studies investigating effects of speaking rate on speech production and speech perception reveals an apparent conflict between acoustic data from speech production and the acoustic parameters typically manipulated in speech perception experiments. This note is intended to address the apparent conflict in the literature by examining both production and perception studies in the extant literature, and by analyzing new data on the effects of speaking rate on Voice-Onset Time (VOT) production in English. Subjects were asked to read CVC words in context at both slow and fast rates of speech, and the relationship between VOT and vowel duration across changes in speaking rate was then examined. The data for Voiceless stop plus sound sequences indicate that as speaking rate slows both VOT and vowel duration increase in almost equal proportions. Importantly, there is no evidence that VOT and vowel length vary inversely such that as VOT increases, vowel length decreases. In contrast, most perception experiments examining the effects of speaking rate on VOT use stimulus parameters that do vary inversely VOT and vowel length. Thus, the perceptual the effects obtained under such conditions may not be appropriately attributable to perceptual effects of speaking rate on phonetic categorization, but rather may be due to other perceptual effects.

  • effects of speaking rate on Voice Onset Time in thai french and english
    Journal of Phonetics, 1997
    Co-Authors: R H Kessinger, Sheila E. Blumstein
    Abstract:

    Abstract This study investigated the effect of speaking rate on stop consonant production in three languages which have different phonetic categories of voicing. Voice-Onset Time (VOT) distributions and mean VOT values were examined for initial labial and alveolar stop consonants produced in CV(C) words in isolation and in context at both slow and fast rates of speech. Results revealed that the short lag category did not change as a function of speaking rate in any of the three languages examined, although VOT values for long lag (Thai and English) and pre-Voiced (Thai and French) stop consonants were affected by changes in speaking rate. However, the shift of the long lag and pre-Voiced categories toward the short lag VOT values in the fast rate condition resulted in little overlap between voicing categories. Implications of these results for the nature of phonetic categories are discussed.

Kenneth Hyltenstam - One of the best experts on this subject based on the ideXlab platform.

  • effects of age and speaking rate on Voice Onset Time the production of Voiceless stops by near native l2 speakers
    Studies in Second Language Acquisition, 2015
    Co-Authors: Katrin Stolten, Niclas Abrahamsson, Kenneth Hyltenstam
    Abstract:

    As part of a research project on the investigation of second language (L2) ultimate attainment in 41 Spanish early and late near-native speakers of L2 Swedish, the present study reports on Voice Onset Time (VOT) analyses of the production of Swedish word-initial Voiceless stops, /p t k/. Voice Onset Time is analyzed in milliseconds as well as in percentages of word duration, thereby accounting for speaking rate effects. The results revealed an overall age effect on VOT production; however, this age effect became salient and statistically significant for all three stops only when speaking rate was taken into consideration. Similarly, when speaking rate was accounted for, only a small minority of the late learners exhibited actual nativelike L2 behavior, and most (but far from all) early learners performed within native-speaker range. The results are taken as an indication for relative VOT, as opposed to absolute VOT, constituting a reliable measure of nativelike L2 stop production, which has important implications for future research on age effects and maturational constraints in L2 acquisition.

  • effects of age of learning on Voice Onset Time categorical perception of swedish stops by near native l2 speakers
    Language and Speech, 2014
    Co-Authors: Katrin Stolten, Niclas Abrahamsson, Kenneth Hyltenstam
    Abstract:

    This study examined the effects of age of Onset (AO) of L2 acquisition on the categorical perception of the voicing contrast in Swedish word-initial stops varying in Voice Onset Time (VOT). Three voicing continua created on the basis of natural Swedish word pairs with /p-b/, /t-d/, /k-/ in initial position were presented to 41 Spanish early (AO 12) near-native speakers of L2 Swedish. Fifteen native speakers of Swedish served as controls. Categorizations were influenced by AO and listener status as L1/L2 speaker, in that the late learners deviated the most from native-speaker perception. In addition, only a small minority of the late learners perceived the voicing contrast in a way comparable to native-speaker categorization, while most early L2 learners demonstrated nativelike categorization patterns. However, when the results were combined with the L2 learners' production of Swedish Voiceless stops (Stolten, 2005; Stolten, Abrahamsson & Hyltenstam, in press), nativelike production and perception was never found among the late learners, while a majority of the early learners still exhibited nativelike production and perception. It is concluded that, despite their being perceived as mother-tongue speakers of Swedish by native listeners, the late learners do not, after detailed phonetic scrutiny, exhibit a fully nativelike command of Swedish VOT. Consequently, being near-native rather than nativelike speakers of their second language, these individuals do not constitute the evidence necessary to reject the hypothesis of one or several critical (or sensitive) periods for language acquisition.

Joseph C Arezzo - One of the best experts on this subject based on the ideXlab platform.

  • intracortical responses in human and monkey primary auditory cortex support a temporal processing mechanism for encoding of the Voice Onset Time phonetic parameter
    Cerebral Cortex, 2004
    Co-Authors: Mitchell Steinschneider, Igor O Volkov, Joseph C Arezzo, Yonatan I Fishman, Matthew A Howard
    Abstract:

    This study tests the hypothesis that temporal response patterns in primary auditory cortex are potentially relevant for Voice Onset Time (VOT) encoding in two related experiments. The first experiment investigates whether temporal responses reflecting VOT are modulated in a way that can account for boundary shifts that occur with changes in first formant (F1) frequency, and by extension, consonant place of articulation. Evoked potentials recorded from Heschl’s gyrus in a patient undergoing epilepsy surgery evaluation are examined. Representation of VOT varies in a manner that reflects the spectral composition of the syllables and the underlying tonotopic organization. Activity patterns averaged across extended regions of Heschl’s gyrus parallel changes in the subject’s perceptual boundaries. The second experiment investigates whether the physiological boundary for detecting the sequence of two acoustic elements parallels the psychoacoustic result of ~20 ms. Population responses evoked by two-tone complexes with variable tone Onset Times (TOTs) in primary auditory cortex of the monkey are examined. Onset responses evoked by both the first and second tones are detected at a TOT separation as short as 20 ms. Overall, parallels between perceptual and physiological results support the relevance of a population-based temporal processing mechanism for VOT encoding.

  • representation of the Voice Onset Time vot speech parameter in population responses within primary auditory cortex of the awake monkey
    Journal of the Acoustical Society of America, 2003
    Co-Authors: Mitchell Steinschneider, Yonatan I Fishman, Joseph C Arezzo
    Abstract:

    Voice Onset Time (VOT) signifies the interval between consonant Onset and the start of rhythmic vocal-cord vibrations. Differential perception of consonants such as /d/ and /t/ is categorical in American English, with the boundary generally lying at a VOT of 20–40 ms. This study tests whether previously identified response patterns that differentially reflect VOT are maintained in large-scale population activity within primary auditory cortex (A1) of the awake monkey. Multiunit activity and current source density patterns evoked by the syllables /da/ and /ta/ with variable VOTs are examined. Neural representation is determined by the tonotopic organization. Differential response patterns are restricted to lower best-frequency regions. Response peaks Time-locked to both consonant and voicing Onsets are observed for syllables with a 40- and 60-ms VOT, whereas syllables with a 0- and 20-ms VOT evoke a single response Time-locked only to consonant Onset. Duration of aspiration noise is represented in higher best-frequency regions. Representation of VOT and aspiration noise in discrete tonotopic areas of A1 suggest that integration of these phonetic cues occurs in secondary areas of auditory cortex. Findings are consistent with the evolving concept that complex stimuli are encoded by synchronized activity in large-scale neuronal ensembles.

  • physiologic correlates of the Voice Onset Time boundary in primary auditory cortex a1 of the awake monkey temporal response patterns
    Brain and Language, 1995
    Co-Authors: Mitchell Steinschneider, Charles E Schroeder, Joseph C Arezzo, Herbert G Vaughan
    Abstract:

    Behavioral studies in animals support the view that categorical, phonetic phenomena are based upon specific response properties of the auditory system. This study investigated physiologic responses reflecting the phonetic parameter of Voice Onset Time (VOT). We examined multiunit activity (MUA) in the primary auditory cortex (A1) of awake monkeys elicited by the consonant-vowel syllables /da/ and /ta/ that varied in VOT from 0 to 60 msec. Two temporal response patterns encode VOT. The first pattern contains responses Time-locked to stimulus Onset and to the Onset of voicing. In 10 of 17 electrode penetrations that display this pattern, MUA reflects the VOT perceptual boundary by containing a prominent response to voicing Onset only for /ta/ stimuli. The second pattern contains responses phase-locked to the periodic portion of the syllables. MUA exhibiting this temporal pattern does not display categorical-like properties. We conclude that specific temporal response patterns in A1 reflect the perceptual boundary for VOT and may represent a physiologic correlate for categorical perception of this phonetic parameter.

  • speech evoked activity in primary auditory cortex effects of Voice Onset Time
    Electroencephalography and Clinical Neurophysiology, 1994
    Co-Authors: Mitchell Steinschneider, Charles E Schroeder, Joseph C Arezzo, Herbert G Vaughan
    Abstract:

    Abstract Neural encoding of temporal speech features is a key component of acoustic and phonetic analyses. We examined the temporal encoding of the syllables /da/ and /ta/, which differ along the temporally based, phonetic parameter of Voice Onset Time (VOT), in primary auditory cortex (A1) of awake monkeys using concurrent multilaminar recordings of auditory evoked potentials (AEP), the derived current source density, and multiunit activity. A general sequence of A1 activation consisting of a lamina-specific profile of parallel and sequential excitatory and inhibitory processes is described. VOT is encoded in the temporal response patterns of phase-locked activity to the periodic speech segments and by “on” responses to stimulus and voicing Onset. A transformation occurs between responses in the thalamocortical (TC) fiber input and A1 cells. TC fibers are more likely to encode VOT with “on” responses to stimulus Onset followed by phase-locked responses during the Voiced segment, whereas A1 responses are more likely to exhibit transient responses both to stimulus and voicing Onset. Relevance to subcortical speech processing, the human AEP and speech psychoacoustics are discussed. A mechanism for categorical differentiation of Voiced and unVoiced consonants is proposed.