Blog Archives

Systematic Studies of Modified Vocalization: Speech Production Changes During a Variation of Metronomic Speech in Persons Who Do and Do Not Stutter

The most common way to induce fluency using rhythm requires persons who stutter to speak one syllable or one word to each beat of a metronome, but stuttering can also be eliminated when the stimulus is of a particular duration (e.g., 1 s). The present study examined stuttering frequency, speech production changes, and speech naturalness during rhythmic speech that alternated 1 s of reading with 1 s of silence. A repeated-measures design was used to compare data obtained during a control reading condition and during rhythmic reading in 10 persons who stutter (PWS) and 10 normally fluent controls. Ratings for speech naturalness were also gathered from naïve listeners. Results showed that mean vowel duration increased significantly, and the percentage of short phonated intervals decreased significantly, for both groups from the control to the experimental condition. Mean phonated interval length increased significantly for the fluent controls. Mean speech naturalness ratings during the experimental condition were approximately 7 on a 1-9 scale (1 = highly natural; 9 = highly unnatural), and these ratings were significantly correlated with vowel duration and phonated intervals for PWS. The findings indicate that PWS may be altering vocal fold vibration duration to obtain fluency during this rhythmic speech style, and that vocal fold vibration duration may have an impact on speech naturalness during rhythmic speech. Future investigations should examine speech production changes and speech naturalness during variations of this rhythmic condition.

from Journal of Fluency Disorders

Differential effects of perturbation direction and magnitude on the neural processing of voice pitch feedback

Corresponding changes in vocal and neural responses to upward and downward voice pitch feedback perturbations suggest that the N1 and P2 components of ERPs reflect neural concomitants of the vocal responses.

from Clinical Neurophysiology

Systematic Studies of Modified Vocalization: Effects of Speech Rate and Instatement Style During Metronome Stimulation

Conclusion: Results confirm that speech rate and instatement style can influence speech production variables during the production of fluency-inducing conditions. Future studies of normally fluent speech and of stuttered speech must control both features and should further explore the importance of voice onset time, which may be influenced by rate during metronome stimulation in a way that the other variables are not.

from the Journal of Speech, Language, and Hearing Research

Induced Unilateral Vocal Fold Paralysis and Recovery Rapidly Modulate Brain Areas Related to Phonatory Behavior: A Case Study

The decrease in activity during iUVFP and the significantly increased activity during the recovery phase likely represent immediate neuroplastic events occurring within minutes of nerve blockade. Recovery-related changes in the BOLD response are hypothesized to be associated with a recalibration of the system after return of normal laryngeal function.

from the Journal of Voice

A functional role for the ventrolateral prefrontal cortex in non-spatial auditory cognition

Spatial and non-spatial sensory information is hypothesized to be evaluated in parallel pathways. In this study, we tested the spatial and non-spatial sensitivity of auditory neurons in the ventrolateral prefrontal cortex (vPFC), a cortical area in the non-spatial pathway. Activity was tested while non-human primates reported changes in an auditory stimulus’ spatial or non-spatial features. We found that vPFC neurons were reliably modulated during a non-spatial auditory task but were not modulated during a spatial auditory task. The degree of modulation during the non-spatial task correlated positively with the monkeys’ behavioral performance. These results are consistent with the hypotheses that the vPFC is part of a circuit involved in non-spatial auditory processing and that the vPFC plays a functional role in non-spatial auditory cognition.

from the Proceedings of the National Academy of Sciences of the United States of America

Establishing a Basic Speech Repertoire without Using NSOME: Means, Motive, and Opportunity

Children who are performing at a prelinguistic level of vocal communication present unique issues related to successful intervention relative to the general population of children with speech disorders. These children do not consistently use meaning-based vocalizations to communicate with those around them. General goals for this group of children include stimulating more mature vocalization types and connecting these vocalizations to meanings that can be used to communicate consistently with persons in their environment. We propose a means, motive, and opportunity conceptual framework for assessing and intervening with these children. This framework is centered on stimulation of meaningful vocalizations for functional communication. It is based on a broad body of literature describing the nature of early language development. In contrast, nonspeech oral motor exercise (NSOME) protocols require decontextualized practice of repetitive nonspeech movements that are not related to functional communication with respect to means, motive, or opportunity for communicating. Successful intervention with NSOME activities requires adoption of the concept that the child, operating at a prelinguistic communication level, will generalize from repetitive nonspeech movements that are not intended to communicate with anyone to speech-based movements that will be intelligible enough to allow responsiveness to the child’s wants and needs from people in the environment. No evidence from the research literature on the course of speech and language acquisition suggests that this conceptualization is valid.

from Seminars in Speech and Language

Cortical Sensorimotor Control in Vocalization: A Functional Magnetic Resonance Imaging Study

from Laryngoscope

Background: Verbal communication is a human feature and volitional vocalization is its basis. However, little is known regarding the cortical areas involved in human vocalization.

Methods: Therefore, functional magnetic resonance imaging at 3 Tesla was performed in 16 healthy adults to evaluate brain activations related to voice production. The main experiments included tasks involving motor control of laryngeal muscles with and without intonation. In addition, reference mappings of the sensorimotor hand area and the auditory cortices were performed.

Results: Related to vocalization, in addition to activation of the most lateral aspect of the primary sensorimotor cortex close to the Sylvian fissure (M1c), we found activations medially (M1a) and laterally (M1b) of the well-known sensorimotor hand area. Moreover, the supplementary motor area and the anterior cingulate cortex were activated.

Conclusions: Although M1a could be ascribed to motor control of breathing, M1b has been associated with laryngeal motor control. Consequently, even though M1c represents a laryngeal sensorimotor area, its exclusiveness as suggested previously could not be confirmed. Activations in the supplementary motor area and anterior cingulate cortex were ascribed to “vocal-motor planning.” The present data provide the basis for further functional magnetic resonance imaging studies in patients with neurological laryngeal disorders.

Respiratory Movement Patterns during Vocalizations at 7-and 11-Months of Age

from the Journal of Speech, Language, and Hearing Research

Purpose: The present investigation was designed to study the modulation of abdomen and rib cage movements during vocalization over a period of development associated with rapid decreases in the compliance of the chest wall.

Method: Rib cage and abdominal kinematics were recorded during spontaneous vocalizations in 7-and 11-month old infants. Principal component analysis (PCA) was used to represent each infant’s abdomen and rib cage traces as the weighted sum of a small number of PC waveforms.

Results: The fundamental periods of infants’ PC waveforms in the 11-month group were significantly shorter than those in the 7-month group. In addition, the variance contributed by PCs describing unidirectional patterns of respiratory movement decreased in the 11-month group while the variances contributed by PCs describing modulated patterns of movement increased. Lastly, the extent to which abdomen and rib cage movements predicted the duration of corresponding vocalizations also increased significantly in the 11-month group compared to the 7-month group.

Conclusions: The findings of the present study were consistent with the hypothesis that decreases in the compliance of the chest wall result in more rapid modulation of chest wall movements and greater control of those movements by the developing neuromuscular system.