Ingo Hertrich - Academia.edu (original) (raw)

Papers by Ingo Hertrich

Research paper thumbnail of Time course and lateralization of evo complex pitch pr

To assess pitch-related brain lateralization effects, evoked magnetic fields in response to dicho... more To assess pitch-related brain lateralization effects, evoked magnetic fields in response to dichotic rippled noise (RN) were recorded by means of whole-head magnetoencephalography (MEG). Four dichotic stimulus constellations (111or 133-Hz RN to one ear, white noise to the other) were applied in randomized order. The evoked fields delineated three stages of central-auditory processing. (1) Attention-dependent ear × hemisphere interactions were observed as early as the M50 field (50-80 ms post stimulus onset), presumably reflecting early streaming of auditory information. (2) The relatively late M100 field (136 ms) was significantly lateralized to the left hemisphere, but showed a pitch-related modulation of rightrather than left-hemisphere activity. The observed interaction between periodic and aperiodic signal components suggests this time window to reflect pitch-synchronous spectral evaluation. (3) A time window centered at 192 ms showed a main effect of RN pitch, presumably due to...

Research paper thumbnail of Magnetic Brain Activity Tracing the Perceived Speech Signal Regarding Envelope, Syllable Onsets, and Pitch Periodicity

Continuous speech evokes electrophysiological brain activity phase-locked to the speech envelope ... more Continuous speech evokes electrophysiological brain activity phase-locked to the speech envelope (ENV), resembling the N100 responses to single acoustic events. Using magnetoencophalography (MEG), the present study investigated further MEG components that directly reflect acoustic properties of continuous speech signals, i.e., a derivate of the envelope that can be taken as a physical marker of syllable onsets (SYL), and a pitch periodicity signal (PIT) obtained by bandpass filtering of the rectified speech signal. The participants (n = 10) listened to natural or formantsynthesized speech at a moderately fast or ultrafast speaking rate. As expected, the MEG crosscorrelation function with ENV showed a rightlateralized M100-like response with a source in the region of the central auditory system. Regarding the SYL derivate, in addition to auditory M50/M100-like responses a late, more anterior M50-like source component could be isolated. The cross-correlate of MEG data with the PIT der...

Research paper thumbnail of Is impaired intonation in speakers suffering from Parkinson's disease caused at a motor or at a planning level?

Research paper thumbnail of Processing German Vowel Quantity: Categorical Perception or Perceptual Magnet Effect?

The German vowel system shows a complex structure based on the interaction between vowel duration... more The German vowel system shows a complex structure based on the interaction between vowel duration and formant structures between short and long cognates. This leads to the question how vowel duration is processed. The perception of vowel duration in German native speakers was tested by an identification test, a goodness rating and an adaptive discrimination test. The test results show a sharp boundary between the short and the long category. Furthermore, the category border was characterized by bad goodness ratings in comparison to within-category stimuli and a maximum in discrimination performance regarding subtle durational differences. These results meet the criteria of both the perceptual magnet effect and categorical perception.

Research paper thumbnail of Kinematic Analysis of Lower Lip-Jaw and Tongue-Jaw Interactions During Syllable Repetitions : Some Aspects of Motor Equivalence

A rate-controlled syllable repetition task (/pa/, /pi/, /ta/, /ti/; 3 and 5 syllables per second)... more A rate-controlled syllable repetition task (/pa/, /pi/, /ta/, /ti/; 3 and 5 syllables per second) was used to study the effects of jaw lower lip and jaw tongue tip coordination on differential movement amplitudes. In some cases, significant negative covariation across repetitions emerged, but the opposite constellation was observed as well. Considering the systematic effects of vowel context and syllable rate, the jaw showed some independency from the lower lip and the tongue. However, the differential functional role of jaw contribution to the compound gestures varied across speakers and conditions. These findings are at variance with the suggestion of a speaker-independent gestural organization of speech units at the stage of phonological processing.

Research paper thumbnail of Phonological Aspects of Audiovisual Speech Perception

Based on magnetoencephalographic (MEG) measurements, this contribution tries to delineate a seque... more Based on magnetoencephalographic (MEG) measurements, this contribution tries to delineate a sequence of processing stages engaged in audiovisual (AV) speech p erception, giving rise, finally, to the fusion o f phonological features derived from auditory and v isual input. Although the two channels interact even within early time windows s uch as the a uditory M50 field, the definite percept appears to emerge a t a relatively late stage (> 250 ms after the onset of the acoustic stimulus). Most noteworthy, the obtained d ata indicate visual motion to be encoded as categorical information even prior to AV fusion, as demonstrated b y a non-linear visual /ta/ - /pa/ effect (within the time interval of the auditorily evoked M100 field) upon the strength of a magnetic source localized ou tside the a uditory cortex. Taken together, these findings indicate, first, modality-specific sensory input to be transformed into p honetic features prior to the generation o f a definite phonological ...

Research paper thumbnail of Modelling voiceless speech segments by means of an additive procedure based on the computation of formant sinusoids

A previously developed vowel synthesis algorithm implements formants as sinusoids, amplitude- and... more A previously developed vowel synthesis algorithm implements formants as sinusoids, amplitude- and phase-modulated by the fundamental frequency (Hertrich and Ackermann, 1999, Journal of the Acoustical Society of America, 106, 29882990). The present study extends this approach to the modelling of the ac oustic c haracteristics of aperiodic speech segments. To these e nds, a voiceless s ignal component i s generated by adding at each sample point a random parameter onto the formants' phase progression. Voiceless stop consonants then can be modelled, e.g., by combining a release burst, i.e., an interval in which the formant sinusoids abruptly increase a nd gradually decrease in amplitude, with formantshaped noise components, representing inter-articulator frication, aspiration, and breathy vowel onset.

Research paper thumbnail of The Margins of the Language Network in the Brain

Frontiers in Communication

This review paper summarizes the various brain modules that are involved in speech and language c... more This review paper summarizes the various brain modules that are involved in speech and language communication in addition to a left-dominant “core” language network that, for the present purpose, has been restricted to elementary formal-linguistic and more or less disembodied functions such as abstract phonology, syntax, and very basic lexical functions. This left-dominant perisylvian language network comprises parts of inferior frontal gyrus, premotor cortex, and upper temporal lobe, and a temporoparietal interface. After introducing this network, first, the various roles of neighboring and functionally connected brain regions are discussed. As a second approach, entire additional networks were considered rather than single regions, mainly motivated by resting-state studies indicating more or less stable connectivity patterns within these networks. Thirdly, some examples are provided for language tasks with functional demands exceeding the operating domain of the core language network. The rationale behind this approach is to present some outline of how the brain produces and perceives language, accounting, first, for a bulk of clinical studies showing typical forms of aphasia in case of left-hemispheric lesions in the core language network and second, for wide-spread activation patterns beyond this network in various experimental studies with language tasks. Roughly, the brain resources that complement the core language system in a task-specific way can be described as a number of brain structures and networks that are related to (1) motor representations, (2) sensory-related representations, (3) non-verbal memory structures, (4) affective/emotional processing, (5) social cognition and theory of mind, (6) meaning in context, and (7) cognitive control. After taking into account all these aspects, first, it seems clear that natural language communication cannot really work without additional systems. Second, it also becomes evident that during language acquisition the core language network has to be built up from outside, that is, from various neuronal activations that are related to sensory input, motor imitation, nursing, pre-linguistic sound communication, and pre-linguistic pragmatics. Furthermore, it might be worth considering that also in cases of aphasia the language network might be restored by being trained from outside.

Research paper thumbnail of V10. Learning to comprehend time-compressed speech affects premotor and cerebellar regions in late-blind and normally sighted subjects

Clinical Neurophysiology

Individuals suffering from vision loss of a peripheral origin may learn to understand spoken lang... more Individuals suffering from vision loss of a peripheral origin may learn to understand spoken language at a rate of up to about 22 syllables per second (syl/s), exceeding by far the maximum performance level of untrained listeners (ca. 8 syl/s). Previous findings (Dietrich et al., 2013, BMC Neuroscience) indicate that, in addition to the "classical" language zones (left inferior frontal gyrus, bilateral middle temporal gyrus), right visual cortex (V1), left supplementary motor area (SMA), and cerebellum contribute to the processing of accelerated speech in blind subjects. As an extension, the present training experiment using functional magnetic resonance imaging (fMRI) addresses the issue whether acquisition of ultra-fast (18 syl/s) speech perception skills induces central-visual hemodynamic activation in late-blind participants. Furthermore, we asked to what extent subjects with normal or residual vision can improve understanding of accelerated verbal utterances and whether differential training effects for sighted as compared to blind subjects can be demonstrated. To these ends, prior to and after a training period of ca. six months, fMRI was performed while subjects were listening to forward and time-reversed sentence utterances of a moderately fast (8 syl/s) or an ultra-fast syllable rate (18 syl/s). Eight participants, varying in the amount of residual visual functions, considerably improved their comprehension of ultra fast speech comprehension (pre-training: 9%, SD=13.4, post-training: 70%, SD=16.9; correct words in a sentence repetition task). Among other regions, left SMA, bilateral cerebellum, and right V1 showed a significant interaction (ANOVA) of the factors rate (8 vs. 18 syl/s) and stage (untrained vs. trained). After training, during the ultra-fast speech condition all subjects displayed an increase of hemodynamic activation in left SMA, and cerebellar activation was increased in five of eight participants. Training-induced hemodynamic activation of the central-visual system was only found in subjects with very low visual acuity. Thus, perceptual learning seems to involve SMA-cerebellar circuits, primarily known from motor learning tasks. It can be assumed that SMA and cerebellum contribute to a mechanism of time-critical processing that is required for the reconstruction of the syllabic structure ultra-fast speech during lexical encoding toward verbal working memory. Furthermore, in spite of similar behavioral performance, trained "experts" appear to use distinct strategies of ultra-fast speech processing depending on whether the occipital cortex is still deployed for visual processing (Fig. 1).

Research paper thumbnail of Coarticulation in Slow Speech: Durational and Spectral Analysis

Language and Speech

Durational and spectral measures of anticipatory as well as perseverative coarticulation were obt... more Durational and spectral measures of anticipatory as well as perseverative coarticulation were obtained from the acoustic speech signal of German sentence utterances produced by six young female speakers at comfortable and at slowed speech rate. The test sentences comprised a systematically varied nonsense word embedded into a carrier phrase. Anticipatory and perseverative coarticulation were characterized by different patterns of durational and spectral features. Inter-speaker variability was considerable, particularly with respect to anticipatory vowel-to-vowel coarticulation. As a rule, slowing of speaking rate resulted in a decrease of perseverative coarticulation in the presence of unchanged anticipatory effects. In conclusion, these data corroborate the suggestion that different mechanisms underlie anticipatory and perseverative coarticulation.

Research paper thumbnail of Neuromagnetic signatures of syllable processing in fetuses and infants provide no evidence for habituation

Early human development, 2016

Habituation, as a basic form of learning, is characterized by decreasing amplitudes of neuronal r... more Habituation, as a basic form of learning, is characterized by decreasing amplitudes of neuronal reaction following repeated stimuli. Recent studies indicate that habituation to pure tones of different frequencies occurs in fetuses and infants. Neural processing of different syllables in fetuses and infants was investigated. An auditory habituation paradigm including two different sequences of syllables was presented to each subject. Each sequence consisted of eight syllables (sequence /ba/: 5× /ba/, 1× /bi/ (dishabituator), 2× /ba/; sequence /bi/: 5× /bi/, 1× /ba/ (dishabituator), 2× /bi/). Each subject was stimulated with 140 sequences. Neuromagnetic signatures of auditory-evoked responses (AER) were recorded by fetal magnetoencephalography (fMEG). Magnetic brain signals of N=30 fetuses (age: 28-39weeks of gestation) and N=28 infants (age: 0-3months) were recorded. Forty-two of the 60 fetal recordings and 29 of the 58 infant recordings were included in the final analysis. AERs were...

Research paper thumbnail of Accuracy of lip movement analysis. Comparison between electromagnetic articulography and an optical two-camera device

Forschungsberichte Institut Fur Phonetik Und Sprachliche Kommunikation Der Universitat Munchen, 1997

The aim of the present study was to determine the accuracy of Electromagnetic Articulography (EMA... more The aim of the present study was to determine the accuracy of Electromagnetic Articulography (EMA) under in-vivo conditions by comparing its results to measurements performed with an optoelectronic system (ELITE). The Elite system, based on two cameras emitting infra-red light, allows the tracking of 3-dimensional movements of reflectors attached to the points of interest relative to the space in which the cameras are fixed. In contrast, EMA provides a twodimensional representation of the trajectories of small receiver coils within the mid-sagittal plane of a helmet to which three larger transmitter coils are attached. For the purpose of the present study two EMA receiver coils were attached to the upper and lower lip, respectively. Similarly, two ELITE reflectors were stuck on top of these coils. The test material consisted of German sentences of the type "Ich habe gepVpe gelesen" (engl. "I have read gepVpe") in which the target vowel V was substituted by /a/, /i/, /u/, or /y/. Eight repetitions of the sentences were produced by a female speaker in randomized order, a) with normal, b) fast, and c) slow rate. The bilabial closing gesture terminating the target vowel was chosen for analysis. The average absolute difference between the EMA and the ELITE data was about .5 mm for movement amplitude, 8 mm/s for peak velocity, and 8 milliseconds for the duration of the closing gesture. With respect to amplitude and velocity, the deviation between the two systems was considerably lower than the standard deviation across the repetitions within each vowel category and speech rate condition. Thus, both methods confirm each other as being adequate to investigate speech gestures.

Research paper thumbnail of Interindividuelle Variabilit�t in Langzeitstrukturen des Sprachsignals

Gesellschaft F R Linguistische Datenverarbeitung, 1987

Research paper thumbnail of Dysarthria in Friedreich's ataxia: Timing of speech segments

Research paper thumbnail of Prosodische St�rungen bei neurologischen Erkrankungen - eine Literatur�bersicht

Fortschr Neurol Psychiat, 1993

Research paper thumbnail of Auswirkungen des Lee Silverman Voice Treatments (LSVT) auf die Prosodie von Sprechern mit M. Parkinson

Sprache · Stimme · Gehör, 2008

... findings. Journal of Voice 1996; 10: 354-361 26 Stelzig Y, Hochhaus W, Gall V,Henneberg A. Ke... more ... findings. Journal of Voice 1996; 10: 354-361 26 Stelzig Y, Hochhaus W, Gall V,Henneberg A. Kehlkopfbefunde bei Patienten mit Morbus Parkinson. ... controls. Movement Disorders 2001; 16: 79-83 46 Sapir S, Ramig L, Hoyt P. et al. ...

Research paper thumbnail of Dysarthria in Friedreich's ataxia: Timing of speech segments

Clinical Linguistics & Phonetics

ABSTRACT

Research paper thumbnail of Ackermann H: Fractal dimension of sustained vowel productions in neurological dysphonias: An acoustic and electroglottographic analysis

Research paper thumbnail of A new method in intonation research using partly controlled, simulated dialogues

Research paper thumbnail of Interindividuelle Variabilität in Langzeitstrukturen des Sprachsignals

Research paper thumbnail of Time course and lateralization of evo complex pitch pr

To assess pitch-related brain lateralization effects, evoked magnetic fields in response to dicho... more To assess pitch-related brain lateralization effects, evoked magnetic fields in response to dichotic rippled noise (RN) were recorded by means of whole-head magnetoencephalography (MEG). Four dichotic stimulus constellations (111or 133-Hz RN to one ear, white noise to the other) were applied in randomized order. The evoked fields delineated three stages of central-auditory processing. (1) Attention-dependent ear × hemisphere interactions were observed as early as the M50 field (50-80 ms post stimulus onset), presumably reflecting early streaming of auditory information. (2) The relatively late M100 field (136 ms) was significantly lateralized to the left hemisphere, but showed a pitch-related modulation of rightrather than left-hemisphere activity. The observed interaction between periodic and aperiodic signal components suggests this time window to reflect pitch-synchronous spectral evaluation. (3) A time window centered at 192 ms showed a main effect of RN pitch, presumably due to...

Research paper thumbnail of Magnetic Brain Activity Tracing the Perceived Speech Signal Regarding Envelope, Syllable Onsets, and Pitch Periodicity

Continuous speech evokes electrophysiological brain activity phase-locked to the speech envelope ... more Continuous speech evokes electrophysiological brain activity phase-locked to the speech envelope (ENV), resembling the N100 responses to single acoustic events. Using magnetoencophalography (MEG), the present study investigated further MEG components that directly reflect acoustic properties of continuous speech signals, i.e., a derivate of the envelope that can be taken as a physical marker of syllable onsets (SYL), and a pitch periodicity signal (PIT) obtained by bandpass filtering of the rectified speech signal. The participants (n = 10) listened to natural or formantsynthesized speech at a moderately fast or ultrafast speaking rate. As expected, the MEG crosscorrelation function with ENV showed a rightlateralized M100-like response with a source in the region of the central auditory system. Regarding the SYL derivate, in addition to auditory M50/M100-like responses a late, more anterior M50-like source component could be isolated. The cross-correlate of MEG data with the PIT der...

Research paper thumbnail of Is impaired intonation in speakers suffering from Parkinson's disease caused at a motor or at a planning level?

Research paper thumbnail of Processing German Vowel Quantity: Categorical Perception or Perceptual Magnet Effect?

The German vowel system shows a complex structure based on the interaction between vowel duration... more The German vowel system shows a complex structure based on the interaction between vowel duration and formant structures between short and long cognates. This leads to the question how vowel duration is processed. The perception of vowel duration in German native speakers was tested by an identification test, a goodness rating and an adaptive discrimination test. The test results show a sharp boundary between the short and the long category. Furthermore, the category border was characterized by bad goodness ratings in comparison to within-category stimuli and a maximum in discrimination performance regarding subtle durational differences. These results meet the criteria of both the perceptual magnet effect and categorical perception.

Research paper thumbnail of Kinematic Analysis of Lower Lip-Jaw and Tongue-Jaw Interactions During Syllable Repetitions : Some Aspects of Motor Equivalence

A rate-controlled syllable repetition task (/pa/, /pi/, /ta/, /ti/; 3 and 5 syllables per second)... more A rate-controlled syllable repetition task (/pa/, /pi/, /ta/, /ti/; 3 and 5 syllables per second) was used to study the effects of jaw lower lip and jaw tongue tip coordination on differential movement amplitudes. In some cases, significant negative covariation across repetitions emerged, but the opposite constellation was observed as well. Considering the systematic effects of vowel context and syllable rate, the jaw showed some independency from the lower lip and the tongue. However, the differential functional role of jaw contribution to the compound gestures varied across speakers and conditions. These findings are at variance with the suggestion of a speaker-independent gestural organization of speech units at the stage of phonological processing.

Research paper thumbnail of Phonological Aspects of Audiovisual Speech Perception

Based on magnetoencephalographic (MEG) measurements, this contribution tries to delineate a seque... more Based on magnetoencephalographic (MEG) measurements, this contribution tries to delineate a sequence of processing stages engaged in audiovisual (AV) speech p erception, giving rise, finally, to the fusion o f phonological features derived from auditory and v isual input. Although the two channels interact even within early time windows s uch as the a uditory M50 field, the definite percept appears to emerge a t a relatively late stage (> 250 ms after the onset of the acoustic stimulus). Most noteworthy, the obtained d ata indicate visual motion to be encoded as categorical information even prior to AV fusion, as demonstrated b y a non-linear visual /ta/ - /pa/ effect (within the time interval of the auditorily evoked M100 field) upon the strength of a magnetic source localized ou tside the a uditory cortex. Taken together, these findings indicate, first, modality-specific sensory input to be transformed into p honetic features prior to the generation o f a definite phonological ...

Research paper thumbnail of Modelling voiceless speech segments by means of an additive procedure based on the computation of formant sinusoids

A previously developed vowel synthesis algorithm implements formants as sinusoids, amplitude- and... more A previously developed vowel synthesis algorithm implements formants as sinusoids, amplitude- and phase-modulated by the fundamental frequency (Hertrich and Ackermann, 1999, Journal of the Acoustical Society of America, 106, 29882990). The present study extends this approach to the modelling of the ac oustic c haracteristics of aperiodic speech segments. To these e nds, a voiceless s ignal component i s generated by adding at each sample point a random parameter onto the formants' phase progression. Voiceless stop consonants then can be modelled, e.g., by combining a release burst, i.e., an interval in which the formant sinusoids abruptly increase a nd gradually decrease in amplitude, with formantshaped noise components, representing inter-articulator frication, aspiration, and breathy vowel onset.

Research paper thumbnail of The Margins of the Language Network in the Brain

Frontiers in Communication

This review paper summarizes the various brain modules that are involved in speech and language c... more This review paper summarizes the various brain modules that are involved in speech and language communication in addition to a left-dominant “core” language network that, for the present purpose, has been restricted to elementary formal-linguistic and more or less disembodied functions such as abstract phonology, syntax, and very basic lexical functions. This left-dominant perisylvian language network comprises parts of inferior frontal gyrus, premotor cortex, and upper temporal lobe, and a temporoparietal interface. After introducing this network, first, the various roles of neighboring and functionally connected brain regions are discussed. As a second approach, entire additional networks were considered rather than single regions, mainly motivated by resting-state studies indicating more or less stable connectivity patterns within these networks. Thirdly, some examples are provided for language tasks with functional demands exceeding the operating domain of the core language network. The rationale behind this approach is to present some outline of how the brain produces and perceives language, accounting, first, for a bulk of clinical studies showing typical forms of aphasia in case of left-hemispheric lesions in the core language network and second, for wide-spread activation patterns beyond this network in various experimental studies with language tasks. Roughly, the brain resources that complement the core language system in a task-specific way can be described as a number of brain structures and networks that are related to (1) motor representations, (2) sensory-related representations, (3) non-verbal memory structures, (4) affective/emotional processing, (5) social cognition and theory of mind, (6) meaning in context, and (7) cognitive control. After taking into account all these aspects, first, it seems clear that natural language communication cannot really work without additional systems. Second, it also becomes evident that during language acquisition the core language network has to be built up from outside, that is, from various neuronal activations that are related to sensory input, motor imitation, nursing, pre-linguistic sound communication, and pre-linguistic pragmatics. Furthermore, it might be worth considering that also in cases of aphasia the language network might be restored by being trained from outside.

Research paper thumbnail of V10. Learning to comprehend time-compressed speech affects premotor and cerebellar regions in late-blind and normally sighted subjects

Clinical Neurophysiology

Individuals suffering from vision loss of a peripheral origin may learn to understand spoken lang... more Individuals suffering from vision loss of a peripheral origin may learn to understand spoken language at a rate of up to about 22 syllables per second (syl/s), exceeding by far the maximum performance level of untrained listeners (ca. 8 syl/s). Previous findings (Dietrich et al., 2013, BMC Neuroscience) indicate that, in addition to the "classical" language zones (left inferior frontal gyrus, bilateral middle temporal gyrus), right visual cortex (V1), left supplementary motor area (SMA), and cerebellum contribute to the processing of accelerated speech in blind subjects. As an extension, the present training experiment using functional magnetic resonance imaging (fMRI) addresses the issue whether acquisition of ultra-fast (18 syl/s) speech perception skills induces central-visual hemodynamic activation in late-blind participants. Furthermore, we asked to what extent subjects with normal or residual vision can improve understanding of accelerated verbal utterances and whether differential training effects for sighted as compared to blind subjects can be demonstrated. To these ends, prior to and after a training period of ca. six months, fMRI was performed while subjects were listening to forward and time-reversed sentence utterances of a moderately fast (8 syl/s) or an ultra-fast syllable rate (18 syl/s). Eight participants, varying in the amount of residual visual functions, considerably improved their comprehension of ultra fast speech comprehension (pre-training: 9%, SD=13.4, post-training: 70%, SD=16.9; correct words in a sentence repetition task). Among other regions, left SMA, bilateral cerebellum, and right V1 showed a significant interaction (ANOVA) of the factors rate (8 vs. 18 syl/s) and stage (untrained vs. trained). After training, during the ultra-fast speech condition all subjects displayed an increase of hemodynamic activation in left SMA, and cerebellar activation was increased in five of eight participants. Training-induced hemodynamic activation of the central-visual system was only found in subjects with very low visual acuity. Thus, perceptual learning seems to involve SMA-cerebellar circuits, primarily known from motor learning tasks. It can be assumed that SMA and cerebellum contribute to a mechanism of time-critical processing that is required for the reconstruction of the syllabic structure ultra-fast speech during lexical encoding toward verbal working memory. Furthermore, in spite of similar behavioral performance, trained "experts" appear to use distinct strategies of ultra-fast speech processing depending on whether the occipital cortex is still deployed for visual processing (Fig. 1).

Research paper thumbnail of Coarticulation in Slow Speech: Durational and Spectral Analysis

Language and Speech

Durational and spectral measures of anticipatory as well as perseverative coarticulation were obt... more Durational and spectral measures of anticipatory as well as perseverative coarticulation were obtained from the acoustic speech signal of German sentence utterances produced by six young female speakers at comfortable and at slowed speech rate. The test sentences comprised a systematically varied nonsense word embedded into a carrier phrase. Anticipatory and perseverative coarticulation were characterized by different patterns of durational and spectral features. Inter-speaker variability was considerable, particularly with respect to anticipatory vowel-to-vowel coarticulation. As a rule, slowing of speaking rate resulted in a decrease of perseverative coarticulation in the presence of unchanged anticipatory effects. In conclusion, these data corroborate the suggestion that different mechanisms underlie anticipatory and perseverative coarticulation.

Research paper thumbnail of Neuromagnetic signatures of syllable processing in fetuses and infants provide no evidence for habituation

Early human development, 2016

Habituation, as a basic form of learning, is characterized by decreasing amplitudes of neuronal r... more Habituation, as a basic form of learning, is characterized by decreasing amplitudes of neuronal reaction following repeated stimuli. Recent studies indicate that habituation to pure tones of different frequencies occurs in fetuses and infants. Neural processing of different syllables in fetuses and infants was investigated. An auditory habituation paradigm including two different sequences of syllables was presented to each subject. Each sequence consisted of eight syllables (sequence /ba/: 5× /ba/, 1× /bi/ (dishabituator), 2× /ba/; sequence /bi/: 5× /bi/, 1× /ba/ (dishabituator), 2× /bi/). Each subject was stimulated with 140 sequences. Neuromagnetic signatures of auditory-evoked responses (AER) were recorded by fetal magnetoencephalography (fMEG). Magnetic brain signals of N=30 fetuses (age: 28-39weeks of gestation) and N=28 infants (age: 0-3months) were recorded. Forty-two of the 60 fetal recordings and 29 of the 58 infant recordings were included in the final analysis. AERs were...

Research paper thumbnail of Accuracy of lip movement analysis. Comparison between electromagnetic articulography and an optical two-camera device

Forschungsberichte Institut Fur Phonetik Und Sprachliche Kommunikation Der Universitat Munchen, 1997

The aim of the present study was to determine the accuracy of Electromagnetic Articulography (EMA... more The aim of the present study was to determine the accuracy of Electromagnetic Articulography (EMA) under in-vivo conditions by comparing its results to measurements performed with an optoelectronic system (ELITE). The Elite system, based on two cameras emitting infra-red light, allows the tracking of 3-dimensional movements of reflectors attached to the points of interest relative to the space in which the cameras are fixed. In contrast, EMA provides a twodimensional representation of the trajectories of small receiver coils within the mid-sagittal plane of a helmet to which three larger transmitter coils are attached. For the purpose of the present study two EMA receiver coils were attached to the upper and lower lip, respectively. Similarly, two ELITE reflectors were stuck on top of these coils. The test material consisted of German sentences of the type "Ich habe gepVpe gelesen" (engl. "I have read gepVpe") in which the target vowel V was substituted by /a/, /i/, /u/, or /y/. Eight repetitions of the sentences were produced by a female speaker in randomized order, a) with normal, b) fast, and c) slow rate. The bilabial closing gesture terminating the target vowel was chosen for analysis. The average absolute difference between the EMA and the ELITE data was about .5 mm for movement amplitude, 8 mm/s for peak velocity, and 8 milliseconds for the duration of the closing gesture. With respect to amplitude and velocity, the deviation between the two systems was considerably lower than the standard deviation across the repetitions within each vowel category and speech rate condition. Thus, both methods confirm each other as being adequate to investigate speech gestures.

Research paper thumbnail of Interindividuelle Variabilit�t in Langzeitstrukturen des Sprachsignals

Gesellschaft F R Linguistische Datenverarbeitung, 1987

Research paper thumbnail of Dysarthria in Friedreich's ataxia: Timing of speech segments

Research paper thumbnail of Prosodische St�rungen bei neurologischen Erkrankungen - eine Literatur�bersicht

Fortschr Neurol Psychiat, 1993

Research paper thumbnail of Auswirkungen des Lee Silverman Voice Treatments (LSVT) auf die Prosodie von Sprechern mit M. Parkinson

Sprache · Stimme · Gehör, 2008

... findings. Journal of Voice 1996; 10: 354-361 26 Stelzig Y, Hochhaus W, Gall V,Henneberg A. Ke... more ... findings. Journal of Voice 1996; 10: 354-361 26 Stelzig Y, Hochhaus W, Gall V,Henneberg A. Kehlkopfbefunde bei Patienten mit Morbus Parkinson. ... controls. Movement Disorders 2001; 16: 79-83 46 Sapir S, Ramig L, Hoyt P. et al. ...

Research paper thumbnail of Dysarthria in Friedreich's ataxia: Timing of speech segments

Clinical Linguistics & Phonetics

ABSTRACT

Research paper thumbnail of Ackermann H: Fractal dimension of sustained vowel productions in neurological dysphonias: An acoustic and electroglottographic analysis

Research paper thumbnail of A new method in intonation research using partly controlled, simulated dialogues

Research paper thumbnail of Interindividuelle Variabilität in Langzeitstrukturen des Sprachsignals

Research paper thumbnail of The Temporal Control of Repetitive Articulatory Movements in Parkinson’s Disease

Recent clinical data indicate that internal cueing mechanisms required for the triggering of move... more Recent clinical data indicate that internal cueing mechanisms required for the triggering of movement sequences are impaired in Parkinson’s disease (PD). Nevertheless, most PD subjects produce maximal syllable repetition rates similar to those observed in healthy control individuals during oral diadochokinesis tasks. There is some evidence that tremor oscillations may pace repetitive movements in Parkinsonians giving rise to hastening phenomena. Conceivably, the performance of PD patients in syllable repetition tasks thus reflects a specific timing deficit, i.e., articulatory hastening. It is the aim of the present study to investigate the contribution of speech hastening to oral diadochokinesis in the presence of internal and external cues. By means of an optoelectric movement analysis system, the displacements of the lips during repetitions of the syllable /pa/ were recorded in two akinetic-rigidPD individuals. Subjects were asked to synchronize labial diadochokinesis to sequences of periodic acoustic stimuli (2.5–6 Hz). One of the PD patients showed speech hastening, i.e., he produced repetitions of 8 to 9 Hz whenever stimulus frequencies exceeded 4 Hz. The other Parkinsonian adequately matched the stimulus frequencies required. However, she achieved a higher diadochokinesis rate in the matching task than under the instruction to repeat ‘‘as fast as possible.’’ Thus, the presence of an external cue improved performance. In conclusion, our data indicate two deficits of the temporal control of repetitive articulatory gestures in PD: speech hastening and impaired self-paced sequencing. These two pathomechanisms may allow to reconcile the controversial findings on oral diadochokinesis in PD reported so far.