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Previous work assessing the effect of additive noise on the postural control system has found a positive effect of additive white noise on postural dynamics. This study covers two separate experiments that were run sequentially to better understand how the structure of the additive noise signal affects postural dynamics, while also furthering our knowledge of how the intensity of auditory stimulation of noise may elicit this phenomenon. Across the two experiments, we introduced three auditory noise stimulations of varying structure (white, pink, and brown noise). Experiment 1 presented the stimuli at 35 dB while Experiment 2 was presented at 75 dB. Our findings demonstrate a decrease in variability of the postural control system regardless of the structure of the noise signal presented, but only for high intensity auditory stimulation. [ABSTRACT FROM AUTHOR]

The aim of the study was to compare the acoustic characteristics of voice between Auditory Brainstem Implantees, Cochlear Implantees and normal hearing children. Voice parameters such as fundamental frequency, formant frequencies, perturbation measures, and harmonic to noise ratio were measured in a total of 30 children out of which 10 were Auditory Brainstem Implantees, 10 were Cochlear Implantees and 10 were normal hearing children. Parametric and nonparametric statistics were done to establish the nature of significance between the three groups. Overall deviancies were seen in the implanted group for all acoustic parameters. However abnormal deviations were seen in individuals with Auditory Brainstem Implants indicating the deficit in the feedback loop impacting the voice characteristics. The deviancy in feedback could attribute to the poor performance in ABI and CI. The CI performed comparatively better when compared to the ABI group indicating a slight feedback loop due to the type of Implant. However, there needs to be additional evidence supporting this and there is a need to carry out the same study using a larger sample size and a longitudinal design. [ABSTRACT FROM AUTHOR]

The present study examined opposing and following vocal responses to altered auditory feedback (AAF) to determine how damage to left-hemisphere brain networks impairs the internal forward model and feedback mechanisms in post-stroke aphasia. Forty-nine subjects with aphasia and sixty age-matched controls performed speech vowel production tasks while their auditory feedback was altered using randomized ± 100 cents upward and downward pitch-shift stimuli. Data analysis revealed that when vocal responses were averaged across all trials (i.e., opposing and following), the overall magnitude of vocal compensation was significantly reduced in the aphasia group compared with controls. In addition, when vocal responses were analyzed separately for opposing and following trials, subjects in the aphasia group showed a significantly lower percentage of opposing and higher percentage of following vocal response trials compared with controls, particularly for the upward pitch-shift stimuli. However, there was no significant difference in the magnitude of opposing and following vocal responses between the two groups. These findings further support previous evidence on the impairment of vocal sensorimotor control in aphasia and provide new insights into the distinctive impact of left-hemisphere stroke on the internal forward model and feedback mechanisms. In this context, we propose that the lower percentage of opposing responses in aphasia may be accounted for by deficits in feedback-dependent mechanisms of audio-vocal integration and motor control. In addition, the higher percentage of following responses may reflect aberrantly increased reliance of the speech system on the internal forward model for generating sensory predictions during vocal error detection and motor control. [ABSTRACT FROM AUTHOR]

The use of virtual reality (VR) has seen significant recent growth and presents opportunities for use in many domain areas. The use of head-mounted displays (HMDs) also presents unique opportunities for the implementation of audio feedback congruent with head and body movements, thus matching intuitive expectations. However, the use of audio in VR is still undervalued and there is a lack of consistency within audio-centedd research in VR. To address this shortcoming and present an overview of this area of research, we conducted a scoping review (n = 121) focusing on the use of audio in HMD-based VR and its effects on user/player experience. Results show a lack of standardisation for common measures such as pleasantness and emphasize the context-specific ability of audio to influence a variety of affective, cognitive, and motivational measures, but are mixed for presence and generally lacking for social experiences and descriptive research. [ABSTRACT FROM AUTHOR]

Speech production is a complex human function requiring continuous feedforward commands together with reafferent feedback processing. These processes are carried out by distinct frontal and temporal cortical networks, but the degree and timing of their recruitment and dynamics remain poorly understood. We present a deep learning architecture that translates neural signals recorded directly from the cortex to an interpretable representational space that can reconstruct speech. We leverage learned decoding networks to disentangle feedforward vs. feedback processing. Unlike prevailing models, we find a mixed cortical architecture in which frontal and temporal networks each process both feedforward and feedback information in tandem. We elucidate the timing of feedforward and feedback-related processing by quantifying the derived receptive fields. Our approach provides evidence for a surprisingly mixed cortical architecture of speech circuitry together with decoding advances that have important implications for neural prosthetics. [ABSTRACT FROM AUTHOR]

In this paper, we describe a proof-of-concept for the implementation of a wearable auditory biofeedback system based on a sensor-instrumented insole. Such a system aims to assist everyday users with static and dynamic exercises for gait rehabilitation interventions by providing auditory feedback based on plantar pressure distribution and automated classification of functional gait disorders. As ground reaction force (GRF) data are frequently used in clinical practice to quantitatively describe human motion and have been successfully used for the classification of gait patterns into clinically relevant classes, a feed-forward neural network was implemented on the firmware of the insoles to estimate the GRFs using pressure and acceleration data. The estimated GRFs approximated well the GRF measurements obtained from force plates. To distinguish between physiological gait and gait disorders, we trained and evaluated a support vector machine with labeled data from a publicly accessible dataset. The automated gait classification was then sonified for auditory feedback. The potential of the implemented auditory feedback for preventive and supportive applications in physical therapy was finally assessed with both expert and non-expert participants. A focus group revealed experts' expectations for the proposed system, while a usability study assessed the clarity of the auditory feedback to everyday users. The evaluation shows promising results regarding the usefulness of our system in this application area. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to assess the impact of induced paresthesia on movement parameters of goal-directed aiming movements to determine how visual and auditory feedback may enhance performance when somatosensory feedback is disrupted. In both experiments, neurotypical adults performed the goal-directed aiming task in four conditions: (i) paresthesia—full vision; (ii) paresthesia—no vision; (iii) no paresthesia—full vision; (iv) no paresthesia—no vision. Targets appeared on a computer screen, vision was obscured using visual occlusion spectacles, and paresthesia was induced with a constant current stimulator. The first and last 20% of trials (early and late performance) were compared to assess adaptability to altered somatosensory input. Experiment 2 added an auditory tone that confirmed successful target acquisitions. When compared to early performance in the no-paresthesia and no-vision conditions, induced paresthesia and no vision led to significantly larger endpoint error toward the body midline in both early and late performance. This finding reveals the importance of proprioceptive input for movement accuracy in the absence of visual feedback. The kinematic results indicated that vision could not fully compensate for the disrupted proprioceptive input when participants experienced induced paresthesia. However, when auditory feedback confirmed successful aiming movements in Experiment 2, participants were able to improve their endpoint variability when experiencing induced paresthesia through changes in movement preparation. [ABSTRACT FROM AUTHOR]

Auditory and somatosensory white noise can stabilize standing balance. However, the differential effects of auditory and tactile noise stimulation on balance are unknown. Prior work on unimodal noise stimulation showed gains in balance with white noise through the auditory and tactile modalities separately. The current study aims to examine whether multimodal noise elicits similar responses to unimodal noise. We recorded the postural sway of healthy young adults who were presented with continuous white noise through the auditory or tactile modalities and through a combination of both (multimodal condition) using a wearable device. Our results replicate previous work that showed that auditory or tactile noise reduces sway variability with and without vision. Additionally, we show that multimodal noise also reduces the variability of sway. Analysis of different frequency bands of sway is typically used to separate open-loop exploratory (< 0.3 Hz) and feedback-driven (> 0.3 Hz) sway. We performed this analysis and showed that unimodal and multimodal white noise affected postural sway variability similarly in both timescales. These results support that the sensory noise effects on balance are robust across unimodal and multimodal conditions and can affect both mechanisms of sway represented in the frequency spectrum. In future work, the parameters of acoustic/tactile manipulation should be optimized for the most effective balance stabilization, and multimodal therapies should be explored for older adults with typical age-related balance instabilities. [ABSTRACT FROM AUTHOR]

• Left-hemisphere stroke is associated with impaired vocal sensorimotor mechanisms. • Aberrant neural oscillations predict vocal sensorimotor deficit in stroke survivors. • Normalization oscillatory brain activities improve vocal communication in stroke. The present study investigated the neural oscillatory correlates of impaired vocal sensorimotor control in left-hemisphere stroke. Electroencephalography (EEG) signals were recorded from 34 stroke and 46 control subjects during speech vowel vocalization and listening tasks under normal and pitch-shifted auditory feedback. Time-frequency analyses revealed aberrantly decreased theta (4–8 Hz) and increased gamma band (30–80 Hz) power in frontal and posterior parieto-occipital regions as well as reduced alpha (8–13 Hz) and beta (13–30 Hz) desynchronization over sensorimotor areas before speech vowel vocalization in left-hemisphere stroke compared with controls. Subjects with the stroke also presented with aberrant modulation of broadband (4–80 Hz) neural oscillations over sensorimotor regions after speech vowel onset during vocalization and listening under normal and altered auditory feedback. We found that the atypical pattern of broadband neural oscillatory modulation was correlated with diminished vocal feedback error compensation behavior and the severity of co-existing language-related aphasia symptoms associated with left-hemisphere stroke. These findings indicate complex interplays between the underlying mechanisms of speech and language and their deficits in post-stroke aphasia. Our data motivate the notion of studying neural oscillatory dynamics as a critical component for the examination of speech and language disorders in post-stroke aphasia. [ABSTRACT FROM AUTHOR]

This study investigated the effect of semantic focus on pitch auditory feedback control in the production of phrasal prosody through an experiment using pitch-shifted auditory feedback. We hypothesized that pitch-shift responses would be mediated by semantic focus because highly informative focus types, such as corrective focus, impose more specific constraints on the prosodic form of a phrase and require greater consistency in the production of pitch excursions compared to sentences with no such focus elements. Twenty-eight participants produced sentences with and without corrective focus while their auditory feedback was briefly and unexpectedly perturbed in pitch by +/−200 cents at the start of the sentence. The magnitude and latency of the reflexive pitch-shift responses were measured as a reflection of auditory feedback control. Our results matched our prediction that corrective focus would elicit larger pitch-shift responses, supporting our hypothesis that auditory feedback control is mediated by semantic focus. [ABSTRACT FROM AUTHOR]

Background: Bodily illusions can be used to investigate the experience of being in a body by manipulating the underlying processes of multisensory integration. Research suggests that people with eating disorders (EDs) may have impairments in visual, interoceptive, proprioceptive, and tactile bodily perception. Furthermore, people with EDs also show abnormalities in integrating multisensory visuo-tactile and visual-auditory signals related to the body, which may contribute to the development of body image disturbances. Visuo-auditory integration abnormalities have been observed also in people with subthreshold ED symptomatology. However, it remains unclear whether these impairments are specific to bodily signals or if they extend to any auditory signals. Methods: We will recruit 50 participants (aged 18–24; females assigned at birth) with ED symptomatology (subthreshold group) and 50 control participants. The Eating Disorder Examination Questionnaire will be administered to screen for ED symptomatology and divide the sample into two groups accordingly (control and subthreshold group using a clinical cut-off score of 2.8). The strength of both illusions will be measured implicitly with estimations of body part position and size, and explicitly with self-report questionnaires. As a secondary aim, regression analysis will be run to test the predictive role of susceptibility for both illusions on interoceptive body awareness (measured by the Multidimensional Assessment of Interoceptive Awareness Scale) and sensory-processing sensitivity (measured by the Highly Sensitive Person Scale). Discussion: Our study may contribute to our understanding of the mechanisms underlying body image disturbances. The results may pave the way for novel clinical interventions targeting early symptoms prior to the development of the disorder in young females. Plain English summary: This study aims to investigate whether individuals with subthreshold eating disorder (ED) symptoms show differences in the integration of proprioceptive and auditory cues in relation to body representation, as compared to healthy controls. This will be examined by focusing on two different body parts (finger and waist) with different levels of emotional significance for individuals with EDs. Participants will be screened for ED symptoms and divided into groups accordingly. The strength of the illusions will be measured using estimations of body part position and size, as well as self-report questionnaires. Regression analysis will be used to assess the predictive role of susceptibility to the body illusions on interoceptive body awareness and sensory-processing sensitivity. The results of this study may have implications for understanding the underlying mechanisms of body image disturbances in EDs, and inform the development of clinical interventions for individuals with subthreshold EDs. [ABSTRACT FROM AUTHOR]

When humans are exposed to a predictable external perturbation, they usually generate anticipatory postural adjustments (APAs), which reduce the effect of potential body disturbance. However, when an external perturbation comes from behind and as such unpredicted, no APAs are generated, which challenges postural control. The aim of this study was to examine whether humans exposed to unpredictable perturbations could generate APAs using an auditory cue. Ten young adults were exposed to external perturbations hitting their shoulders from behind with or without an auditory cue prior to the physical impact. Electromyography (EMG) activities of eight trunk and leg muscles and center-of-pressure (COP) displacements were recorded and analyzed during the anticipatory and compensatory phases of postural control. Outcome measures included the latencies and integrals of muscle activities, COP displacements, and indices of co-contraction and reciprocal activation of muscles. The results showed that young adults were able to rely on an auditory cue to generate APAs prior to external perturbations coming from behind, and they demonstrated stronger APAs with training. Moreover, they utilized co-contraction of ventral and dorsal muscles as their APA response. The outcome provides a foundation for future studies aiming at using auditory cues to facilitate the generation of APAs and improve postural control in people with impaired balance while exposed to perturbations. [ABSTRACT FROM AUTHOR]

The moving Rubber Hand Illusion (mRHI) is a paradigm which investigates the sense of ownership (SoO) and the sense of agency (SoA) towards an artificial hand. This study aimed to highlight the role of the SoA on the development of the SoO according to the information provided by an action-related auditory cue. We expected that a reinforcement of the SoO illusion by the SoA could not occur if the sound of the action was removed. In order to assess the SoO and SoA, 25 participants performed the task in the the active congruent, passive congruent, and active incongruent conditions. Also, the onset time of the SoO in the congruent conditions was reported. The results confirmed our hypothesis, showing that agency did not play a pivotal role in promoting the onset of the ownership illusion if ecological auditory feedback was removed. Further research on the cross-modal assessment of individual bodily self-consciousness is recommended. [ABSTRACT FROM AUTHOR]

Sensory feedback plays an important role in speech motor control. One of the main sources of evidence for this is studies in which online auditory feedback is perturbed during ongoing speech. In motor control, it is therefore crucial to distinguish between sensory feedback and externally generated sensory events. This is called source monitoring. Previous altered feedback studies have taken non-conscious source monitoring for granted, as automatic responses to altered sensory feedback imply that the feedback changes are processed as self-caused. However, the role of conscious source monitoring is unclear. The current study investigated whether conscious source monitoring modulates responses to unexpected pitch changes in auditory feedback. During the first block, some participants spontaneously attributed the pitch shifts to themselves (self-blamers) while others attributed them to an external source (other-blamers). Before Block 2, all participants were informed that the pitch shifts were experimentally induced. The self-blamers then showed a reduction in response magnitude in Block 2 compared with Block 1, while the other-blamers did not. This suggests that conscious source monitoring modulates responses to altered auditory feedback, such that consciously ascribing feedback to oneself leads to larger compensation responses. These results can be accounted for within the dominant comparator framework, where conscious source monitoring could modulate the gain on sensory feedback. Alternatively, the results can be naturally explained from an inferential framework, where conscious knowledge may bias the priors in a Bayesian process to determine the most likely source of a sensory event. [ABSTRACT FROM AUTHOR]

There is a growing need for robots that can be remotely controlled to perform tasks of one's own choice. However, the SoA (Sense of Agency: the sense of recognizing that the motion of an observed object is caused by oneself) is reduced because the subject of the robot motion is identified as external due to shared control. To address this issue, we aimed to suppress the decline in SoA by presenting auditory feedback that aims to blur the distinction between self and others. We performed the tracking task in a virtual environment under four different auditory feedback conditions, with varying levels of automation to manipulate the virtual robot gripper. Experimental results showed that the proposed auditory feedback suppressed the decrease in the SoA at a medium level of automation. It is suggested that our proposed auditory feedback could blur the distinction between self and others, and that the operator attributes the subject of the motion of the manipulated object to himself. [ABSTRACT FROM AUTHOR]

When exposed to a predictable external perturbation, humans typically generate anticipatory postural adjustments (APAs) to minimize potential body disturbance. After a single session of training, individuals demonstrated the ability to rely solely on an auditory cue to elicit appropriate APAs in response to an external postural perturbation. However, whether the generation of APAs requires directional specific training remains unclear. The aim of this study was to assess whether directional-specific training with auditory cues is necessary for the generation of appropriate APA responses. Ten young adults were exposed to external perturbations targeting either their left or right shoulders, with or without an auditory cue prior to the physical impact. Electromyography (EMG) activities of sixteen trunk and leg muscles and center-of-pressure (COP) displacements were recorded and analyzed during the anticipatory and compensatory phases of postural control. Outcome measures included the latencies and integrals of muscle activities, COP displacements, and indices of co-contraction and reciprocal activation of muscles. The results revealed that, after training with right-side perturbations accompanied by an auditory cue, young adults exhibited earlier and more efficient APA responses to right-side perturbations relying only on the auditory cue. Additionally, they displayed earlier APA responses in some muscles to left-side perturbations, although these responses were less efficient. Our findings suggest that young adults could generate effective APAs to external perturbations relying on an auditory cue after a single training session; however, these responses were directional specific. [ABSTRACT FROM AUTHOR]

Some species have evolved the ability to use the sense of hearing to modify existing vocalizations, or even create new ones, which enlarges their repertoires and results in complex communication systems. 1 This ability corresponds to various forms of vocal production learning that are all possessed by humans and independently displayed by distantly related vertebrates. 1,2,3,4,5,6,7 Among mammals, a few species, including the Egyptian fruit bat, 8,9,10 would possess such vocal production learning abilities. 7 Yet the necessity of an intact auditory system for the development of the Egyptian fruit bat typical vocal repertoire has not been tested. Furthermore, a systematic causal examination of learned and innate aspects of the entire repertoire has never been performed in any vocal learner. Here we addressed these gaps by eliminating pups' sense of hearing at birth and assessing its effects on vocal production in adulthood. The deafening treatment enabled us to both causally test these bats' vocal learning ability and discern learned from innate aspects of their vocalizations. Leveraging wireless individual audio recordings from freely interacting adults, we show that a subset of the Egyptian fruit bat vocal repertoire necessitates auditory feedback. Intriguingly, these affected vocalizations belong to different acoustic groups in the vocal repertoire of males and females. These findings open the possibilities for targeted studies of the mammalian neural circuits that enable sexually dimorphic forms of vocal learning. [Display omitted] • Kanamycin treatment successfully suppresses hearing in Egyptian fruit bat pups • Some vocalizations are learned through the sense of hearing; the majority are innate • Males learn to control both the pitch and the frequency filtering of learned calls • Vocal production is sexually dimorphic in Egyptian fruit bats Elie et al. causally demonstrated which vocalizations of the Egyptian fruit bat vocal repertoire depend on an intact auditory system for their typical development. They also found that vocal production learning is sexually dimorphic in this bat species. [ABSTRACT FROM AUTHOR]

The present study investigated how instructions for paying attention to auditory feedback may affect speech error detection and sensorimotor control. Electroencephalography (EEG) and speech signals were recorded from 21 neurologically intact adult subjects while they produced the speech vowel sound /a/ and received randomized ±100 cents pitch-shift alterations in their real-time auditory feedback. Subjects were instructed to pay attention to their auditory feedback and press a button to indicate whether they detected a pitch-shift stimulus during trials. Data for this group was compared with 22 matched subjects who completed the same speech task under altered auditory feedback condition without attentional instructions. Results revealed a significantly smaller magnitude of speech compensations in the attentional-instruction vs. no-instruction group and a positive linear association between the magnitude of compensations and P2 event-related potential (ERP) amplitudes. In addition, we found that the amplitude of P2 ERP component was significantly larger in the attentional-instruction vs. no-instruction group. Source localization analysis showed that this effect was accounted for by significantly stronger neural activities in the right hemisphere insula, precentral gyrus, postcentral gyrus, transverse temporal gyrus, and superior temporal gyrus in the attentional-instruction group. These findings suggest that attentional instructions may enhance speech auditory feedback error detection, and subsequently improve sensorimotor control via generating more stable speech outputs (i.e., smaller compensations) in response to pitch-shift alterations. Our data are informative for advancing theoretical models and motivating targeted interventions with a focus on the role of attentional instructions for improving treatment outcomes in patients with motor speech disorders. • Attentional instructions improve speech auditory feedback error correction mechanisms. • Attentional instructions reduce speech compensation to auditory feedback alterations. • Neural responses to speech feedback error are enhanced following attentional instructions. • Long-latency neural responses correlate with the magnitude of speech error compensation. • Attention instructions modulate neural activity in right hemisphere sensorimotor networks. [ABSTRACT FROM AUTHOR]

Purpose: Auditory feedback (AF) contributes to speech intelligibility (SI) which is vital in social interactions to examine AF effect on SI of adults with cochlear implant (CI). The relationship between age of CI implantation and AF on SI was examined as well. Method: Twenty native Hebrew speaker pre-lingual adults with a hearing loss using CIs from ages 2 to 19 years. Participants were recorded reading excerpts from a book and word lists from MIDBAR test in two situations—with and without using their CIs. Sixteen judges listened to the recordings and rated the speech characteristics of the participants reading the excerpts using an adapted version of Speech Intelligibility Test and Intelligibility Questionnaire for Teachers. Results: Significant differences were found between the SI of words of those who received CI before and after 3 years. AF effect was found only for the older implantation group. The questionnaire indicates good reliability among all the speech characteristics. The speech characteristics most affected by the AF are the disruption of consonants followed by the varied degrees of intonation precision and nasality. Conclusions: AF affects speech characteristics differently and is vital to SI. The use of the adapted version of Speech Intelligibility Test and Intelligibility Questionnaire for Teachers can be used clinically to assess SI and rehabilitation of young adults with CI. AF accessed at a younger age decreases the dependency on AF in later years. [ABSTRACT FROM AUTHOR]

Purpose: Speech production is a complex motor task involving multiple subsystems. The relationships between these subsystems need to be comprehensively investigated to understand the underlying mechanisms of speech production. The goal of this paper is to examine the differential contributions of 1) auditory and somatosensory feedback control mechanisms, and 2) laryngeal and articulatory speech production subsystems on speech motor control at an individual speaker level using altered auditory and somatosensory feedback paradigms. Methods: Twenty young adults completed speaking tasks in which sudden and unpredictable auditory and physical perturbations were applied to the laryngeal and articulatory speech production subsystems. Auditory perturbations were applied to laryngeal or articulatory acoustic features of speech. Physical perturbations were applied to the larynx and the jaw. Pearson-product moment correlation coefficients were calculated between 1) auditory and somatosensory reflexive responses to investigate relationships between auditory and somatosensory feedback control mechanisms, and 2) laryngeal and articulatory reflexive responses as well as acuity measures to investigate the relationship between auditory-motor features of laryngeal and articulatory subsystems. Results: No statistically significant correlations were found concerning the relationships between auditory and somatosensory feedback. No statistically significant correlations were found between auditory-motor features in the laryngeal and articulatory control subsystems. Conclusion: Results suggest that the laryngeal and articulatory speech production subsystems operate with differential auditory and somatosensory feedback control mechanisms. The outcomes suggest that current models of speech motor control should consider decoupling laryngeal and articulatory domains to better model speech motor control processes. [ABSTRACT FROM AUTHOR]

Fine audiovocal control is a hallmark of human speech production and depends on precisely coordinated muscle activity guided by sensory feedback. Little is known about shared audiovocal mechanisms between humans and other mammals. We hypothesized that real-time audiovocal control in bat echolocation uses the same computational principles as human speech. To test the prediction of this hypothesis, we applied state feedback control (SFC) theory to the analysis of call frequency adjustments in the echolocating bat, Hipposideros armiger. This model organism exhibits well-developed audiovocal control to sense its surroundings via echolocation. Our experimental paradigm was analogous to one implemented in human subjects. We measured the bats' vocal responses to spectrally altered echolocation calls. Individual bats exhibited highly distinct patterns of vocal compensation to these altered calls. Our findings mirror typical observations of speech control in humans listening to spectrally altered speech. Using mathematical modeling, we determined that the same computational principles of SFC apply to bat echolocation and human speech, confirming the prediction of our hypothesis. [ABSTRACT FROM AUTHOR]

Background: The potential of auditory feedback for motor learning in the rehabilitation of various diseases has become apparent in recent years. However, since the volume of auditory feedback has played a minor role so far and its influence has hardly been considered, we investigate the volume effect of auditory feedback on gait pattern and gait direction and its interaction with pitch.Methods: Thirty-two healthy young participants were randomly divided into two groups: Group 1 (n = 16) received a high pitch (150-250 Hz) auditory feedback; group 2 (n = 16) received a lower pitch (95-112 Hz) auditory feedback. The feedback consisted of a real-time sonification of the right and left foot ground contact. After an initial condition (no auditory feedback and full vision), both groups realized a 30-minute habituation period followed by a 30-minute asymmetry period. At any condition, the participants were asked to walk blindfolded and with auditory feedback towards a target at 15 m distance and were stopped 5 m before the target. Three different volume conditions were applied in random order during the habituation period: loud, normal, and quiet. In the subsequent asymmetry period, the three volume conditions baseline, right quiet and left quiet were applied in random order.Results: In the habituation phase, the step width from the loud to the quiet condition showed a significant interaction of volume*pitch with a decrease at high pitch (group 1) and an increase at lower pitch (group 2) (group 1: loud 1.02 ± 0.310, quiet 0.98 ± 0.301; group 2: loud 0.95 ± 0.229, quiet 1.11 ± 0.298). In the asymmetry period, a significantly increased ground contact time on the side with reduced volume could be found (right quiet: left foot 0.988 ± 0.033, right foot 1.003 ± 0.040, left quiet: left foot 1.004 ± 0.036, right foot 1.002 ± 0.033).Conclusions: Our results suggest that modifying the volume of auditory feedback can be an effective way to improve gait symmetry. This could facilitate gait therapy and rehabilitation of hemiparetic and arthroplasty patients, in particular if gait improvement based on verbal corrections and conscious motor control is limited. [ABSTRACT FROM AUTHOR]

Human vocal development and speech learning require acoustic feedback, and humans who are born deaf do not acquire a normal adult speech capacity. Most other mammals display a largely innate vocal repertoire. Like humans, bats are thought to be one of the few taxa capable of vocal learning as they can acquire new vocalizations by modifying vocalizations according to auditory experiences. We investigated the effect of acoustic deafening on the vocal development of the pale spear-nosed bat. Three juvenile pale spear-nosed bats were deafened, and their vocal development was studied in comparison with an age-matched, hearing control group. The results show that during development the deafened bats increased their vocal activity, and their vocalizations were substantially altered, being much shorter, higher in pitch, and more aperiodic than the vocalizations of the control animals. The pale spear-nosed bat relies on auditory feedback for vocal development and, in the absence of auditory input, species-atypical vocalizations are acquired. This work serves as a basis for further research using the pale spear-nosed bat as a mammalian model for vocal learning, and contributes to comparative studies on hearing impairment across species. This article is part of the theme issue 'Vocal learning in animals and humans'. [ABSTRACT FROM AUTHOR]

Eye gaze interfaces have been used by people with severe physical impairment to interact with various assistive technologies. If used to control robots, it would be beneficial if individuals could gaze directly at targets in the physical environment rather than have to switch their gaze between a screen with representations of robot commands and the physical environment to see the response of their selection. By using a homogeneous transformation technique, eye gaze coordinates can be mapped between the reference coordinate frame of eye tracker and the coordinate frame of objects in the physical environment. Feedback about where the eye tracker has determined the eye gaze is fixated is needed so users can select targets more accurately. Screen-based assistive technologies can use visual feedback, but in a physical environment, other forms of feedback need to be examined. In this study, an eye gaze system with different feedback conditions (i.e., visual, auditory, vibrotactile, and no-feedback) was tested when participants received visual feedback on a display (on-screen) and when looking directly at the physical environment (off-screen). Target selection tasks in both screen conditions were performed by ten non-disabled adults, three non-disabled children, and two adults and one child with cerebral palsy. Tasks performed with gaze fixation feedback modalities were accomplished faster and with higher success than tasks performed without feedback, and similar results were observed in both screen conditions. No significant difference was observed in performance across the feedback modalities, but participants had personal preferences. The homogeneous transformation technique enabled the use of a stationary eye tracker to select target objects in the physical environment, and auditory and vibrotactile feedback enabled participants to be more accurate selecting targets than without it. Being able to select target objects in the physical environment by eye gaze could make it easier for children with disabilities to control assistive robots, because in this way they do not have to change their focus between a computer screen with commands and the robot. Providing auditory or vibrotactile feedback when using an eye gaze system made it faster and easier to know if a target was being gazed upon. Being able to select targets in the environment using eye gaze could be beneficial for other assistive technology, too, such as destination selection for power wheelchairs. [ABSTRACT FROM AUTHOR]

BACKGROUND: To compare the frequency parameters of voice between children using cochlear implant (CI) and those with normal hearing and establishing a trend of development of voice characteristics across chronological and implant ages. METHODS: The study included 87 children aged 12 to 72 months, with a mean age of 41 months. The subjects were divided into 2 groups: group 1 included 44 children using CIs, and group 2 included 43 children with normal hearing and age-appropriate speech and language characteristics. Both groups were categorized into 3 subgroups based on their chronological ages, group A (12-32 months), B (33-52 months), and C (53-72 months). The CI group (i.e., group 2) was further subdivided based on implant ages as group D (1-4 months), E (5-8 months), and F (9-12 months). RESULTS: Comparison of vocal frequency parameters across chronological ages revealed a decline with increasing age in both groups; however, stability was not maintained in the CI group. There was a statistically significant difference in the vocal frequency parameters between normal hearing children and those with CI. Comparing across implant ages, there was a significant difference between groups D and F. CONCLUSION: For better communication abilities of individuals with CI, along with early implantation and rehabilitation, there is a need to also focus therapy on providing training on speech modulations, especially on voice characteristics. [ABSTRACT FROM AUTHOR]

Accumulating evidence demonstrates that the cerebellum is involved in a variety of cognitive functions. Recently, impaired auditory-motor integration for vocal control has been identified in patients with cerebellar degeneration, characterized by abnormally enhanced vocal compensations for pitch perturbations. However, the causal relationship between the cerebellum and auditory feedback during vocal production remains unclear. By applying anodal transcranial direct current stimulation (a-tDCS) over right cerebellum, the present study investigated cerebellar contributions to auditory-motor processing of feedback errors during vocal pitch regulation. Twenty young adults participated in a frequency-altered-feedback (FAF) task, in which they vocalized vowel sounds and heard their voice unexpectedly pitch-shifted by ± 50 or ± 200 cents. Active or sham cerebellar a-tDCS was applied either prior to or during the FAF task. Compensatory vocal responses to pitch perturbations were measured and compared across the conditions. Active cerebellar a-tDCS led to significantly larger and slower vocal compensations for pitch perturbations than sham stimulation. Moreover, this modulatory effect was observed regardless of the timing of cerebellar a-tDCS as well as the size and direction of the pitch perturbation. These findings provide the first causal evidence that the cerebellum is essentially involved in auditory feedback control of vocal production. Enhanced and slowed vocal compensations caused by cerebellar a-tDCS may be related to its inhibition on the prefrontal cortex that exerts inhibitory control over vocal compensation behavior, suggesting the importance of the cerebrocerebellar connections in this feedback control process. [ABSTRACT FROM AUTHOR]

The neural mechanisms underlying stuttering remain poorly understood. A large body of work has focused on sensorimotor integration difficulties in individuals who stutter, including recently the capacity for sensorimotor learning. Typically, sensorimotor learning is assessed with adaptation paradigms in which one or more sensory feedback modalities are experimentally perturbed in real time. Our own previous work on speech with perturbed auditory feedback revealed substantial auditory‐motor learning limitations in both children and adults who stutter (AWS). It remains unknown, however, which subprocesses of sensorimotor learning are impaired. Indeed, new insights from research on upper limb motor control indicate that sensorimotor learning involves at least two distinct components: (a) an explicit component that includes intentional strategy use and presumably is driven by target error and (b) an implicit component that updates an internal model without awareness of the learner and presumably is driven by sensory prediction error. Here, we attempted to dissociate these components for speech auditory‐motor learning in AWS versus adults who do not stutter (AWNS). Our formant‐shift auditory‐motor adaptation results replicated previous findings that such sensorimotor learning is limited in AWS. Novel findings are that neither control nor stuttering participants reported any awareness of changing their productions in response to the auditory perturbation and that neither group showed systematic drift in auditory target judgments made throughout the adaptation task. These results indicate that speech auditory‐motor adaptation to formant‐shifted feedback relies exclusively on implicit learning processes. Thus, limited adaptation in AWS reflects poor implicit sensorimotor learning. Speech auditory‐motor adaptation to formant‐shifted feedback lacks an explicit component: Reduced adaptation in adults who stutter reflects limitations in implicit sensorimotor learning. [ABSTRACT FROM AUTHOR]

Self‐voice attribution can become difficult when voice characteristics are ambiguous, but functional magnetic resonance imaging (fMRI) investigations of such ambiguity are sparse. We utilized voice‐morphing (self‐other) to manipulate (un‐)certainty in self‐voice attribution in a button‐press paradigm. This allowed investigating how levels of self‐voice certainty alter brain activation in brain regions monitoring voice identity and unexpected changes in voice playback quality. FMRI results confirmed a self‐voice suppression effect in the right anterior superior temporal gyrus (aSTG) when self‐voice attribution was unambiguous. Although the right inferior frontal gyrus (IFG) was more active during a self‐generated compared to a passively heard voice, the putative role of this region in detecting unexpected self‐voice changes during the action was demonstrated only when hearing the voice of another speaker and not when attribution was uncertain. Further research on the link between right aSTG and IFG is required and may establish a threshold monitoring voice identity in action. The current results have implications for a better understanding of the altered experience of self‐voice feedback in auditory verbal hallucinations. [ABSTRACT FROM AUTHOR]

A time-period of turning off cochlear implant (CI) might affect the speech and voice features of the CI users due to loss of auditory feedback monitoring. To evaluate Persian-speaking CI users' speech and voice parameters in a device-on/off experiment. Forty-eight Persian-speaking adults with post-linguistic deafness who had received a unilateral CI and 50 normally-hearing counterparts were recruited. All CI users had to fulfill three phases of speech sampling, including the device-on, device-off (a 5-hourly period), and once again device-on phase. Their Fundamental frequency, Jitter, Shimmer, Harmonics-to-noise ratio, hyper-nasality score, and the percentage of speech intelligibility were assessed for both groups. The findings revealed that the CI-on/off conditions significantly changed cochlear implanted participants' F0, Shimmer, HNR, and hyper-nasality values. However, no statistical differences were observed in Jitter and the percentage of speech intelligibility between the CI and control groups. A short-term auditory deprivation in CI recipients could degrade the speech and voice quality in CI users, so that could change the quality of their speech resonance into hyper-nasality. However, when the CIs were turned on again, the quality of their speech and voice returned to normal-sounding. [ABSTRACT FROM AUTHOR]

Synchronizing movements with an external periodic stimulus, such as tapping your foot along with a metronome, is a remarkable human skill called sensorimotor synchronization. A growing body of literature investigates this process, but experiments require collecting responses with high temporal reliability, which often requires specialized hardware. The current article presents and validates TeensyTap, an inexpensive, highly functional framework with excellent timing performance. The framework uses widely available, low-cost hardware and consists of custom-written open-source software and communication protocols. TeensyTap allows running complete experiments through a graphical user interface and can simultaneously present a pacing signal (metronome), measure movements using a force-sensitive resistor, and deliver auditory feedback, with optional experimenter- specified artificial feedback delays. Movement data is communicated to a computer and saved for offline analysis in a format that allows it to be easily imported into spreadsheet programs. The present work also reports a validation experiment showing that timing performance of TeensyTap is highly accurate, ranking it among the gold standard tools available in the field. Metronome pacing signals are presented with millisecond accuracy, feedback sounds are delivered on average 2 ms following the subjects' taps, and the timing log files produced by the device are unbiased and accurate to within a few milliseconds. The framework allows for a range of experimental questions to be addressed and, since it is open source and transparent, researchers with some technical expertise can easily adapt and extend it to accommodate a host of possible future experiments that have yet to be imagined. [ABSTRACT FROM AUTHOR]

• Speech auditory-motor adaptation to a spectral perturbation was reduced by ∼50% when feedback was delayed by 75 or 115 ms. • Thirty minutes of prior delay exposure without perturbation effectively reduced participants' awareness of the delay. • However, habituation was ineffective in remediating the detrimental effect of delay on speech auditory-motor adaptation. • The dissociation of delay awareness and adaptation suggests that speech auditory-motor learning is mostly implicit. Perceiving the sensory consequences of our actions with a delay alters the interpretation of these afferent signals and impacts motor learning. For reaching movements, delayed visual feedback of hand position reduces the rate and extent of visuomotor adaptation, but substantial adaptation still occurs. Moreover, the detrimental effect of visual feedback delay on reach motor learning—selectively affecting its implicit component—can be mitigated by prior habituation to the delay. Auditory-motor learning for speech has been reported to be more sensitive to feedback delay, and it remains unknown whether habituation to auditory delay reduces its negative impact on learning. We investigated whether 30 min of exposure to auditory delay during speaking (a) affects the subjective perception of delay, and (b) mitigates its disruptive effect on speech auditory-motor learning. During a speech adaptation task with real-time perturbation of vowel spectral properties, participants heard this frequency-shifted feedback with no delay, 75 ms delay, or 115 ms delay. In the delay groups, 50% of participants had been exposed to the delay throughout a preceding 30-minute block of speaking whereas the remaining participants completed this block without delay. Although habituation minimized awareness of the delay, no improvement in adaptation to the spectral perturbation was observed. Thus, short-term habituation to auditory feedback delays is not effective in reducing the negative impact of delay on speech auditory-motor adaptation. Combined with previous findings, the strong negative effect of delay and the absence of an influence of delay awareness suggest the involvement of predominantly implicit learning mechanisms in speech. [ABSTRACT FROM AUTHOR]

This study examined the role of auditory feedback in speech intensity regulation in healthy adults. Ten participants completed five speech production tasks (vowel, sentence reading with/without instructions to ignore feedback, and conversation at one/six meter interlocutor distances) under various altered intensity feedback (AIF) conditions. AIF conditions ranged from plus/minus 2.5, 5, 7.5, 10, 12.5, and 15dB SPL relative to the equivalent (0dB) condition. Speech intensity values obtained for each of the thirteen AIF conditions were submitted to a linear regression analysis and the resulting slope and intercept values were compared. The average slope for the AIF function was found to be significantly steeper for the conversation tasks (-.16) than for the reading tasks (-.07). No difference in slope was found for the comparison of the reading tasks with and without instructions to ignore altered feedback or for the comparison of conversations at one- and six-meter interlocutor distances. It appears that speech tasks with greater communicative demands (i.e. conversation) show larger compensatory responses to AIF than tasks with lower communicative demands (reading). Results suggest that demands of the speech task can interact with the processing of auditory feedback to influence the regulation of speech intensity [ABSTRACT FROM AUTHOR]

Background: Typically, people with Parkinson's Disease (PD) progress to develop a gait pattern that is characterized by quick, short and shuffling steps. Gait cycle is altered and lacks definition and fluidity. Gait training combined with a variety of feedback modalities for PD are usually based on non-immediate and externally-based cues but none of these provide real-time feedback on gait quality and acquired gains tend to abate shortly after rehabilitation. Based on principals of motor learning, our team has developed the Heel2Toe sensor to provide real-time auditory feedback during gait training.Research Question: Is a short-term training using the Heel2Toe sensor feasible and efficient to improve gait in people with PD? Our objectives are to identify the extent of the immediate response to the feedback within the same session and the carry-over response to training and; 2) to identify patients' perceived effects, pleasures and challenges of using the Heel2Toe.Methods: Single-arm, proof-of-concept study. Six people received five sessions of gait training over a 2-3-week period using the Heel2Toe augmented with mobility exercises as an adjunct to gait training. The main outcomes were technically assessed gait parameters collected over a 2-minute walk test, without and with feedback. Heel2Toe signals were analyzed to extract angular velocity(AV), percentage of good steps, average cadence, and AV coefficient of variation(CV).Results: An immediate response to the Heel2Toe use and a carry-over response to the short-term training with the sensor were observed: an increase in AV with a reduction in CV (better heel strike and gait regularity); an increase in %good steps; and a near-optimal and homogeneous cadence (∼100 steps/min), which is equivalent to a moderate-intensity walking.Significance: Gait training using the Heel2Toe sensor is feasible and potentially effective for improving gait quality in people with PD. A definitive trial is a logical next step. [ABSTRACT FROM AUTHOR]

This article presents an overview of information on the development of voice, based on a detailed analysis of the literature. The data demonstrate voice abnormalities in individuals with hearing impairment as compared to individuals with normal hearing. Many researchers believe that the main factor leading to voice abnormalities among hearing-impaired individuals is incorrect auditory feedback resulting from higher hearing thresholds. This lack of feedback leads to abnormal encoding of neuronal patterns in cortical regions of the brain, which results in a disrupted control of internal and external laryngeal muscles. [ABSTRACT FROM AUTHOR]

Auditory feedback has been successfully used to enhance performance in several sports such as golf and dance. The current study used auditory feedback procedures (i.e., a clicker) to improve the performance of 3 students performing a handstand. Handstands are part of a discipline called body weight training, that uses only the weight of an individual's own body to gain strength and body control. A multiple baseline design across four components was used to evaluate the effectiveness of auditory feedback. The results showed that auditory feedback was effective. The students and the trainer were highly satisfied with the auditory feedback procedure. Implications for future research are discussed. [ABSTRACT FROM AUTHOR]

Background: Forward head and rounded shoulder posture (FHRSP) is a poor habitual neck posture among office workers. The posture results in muscle tension and pain around the neck and shoulders and nerve root symptoms in the upper extremities. Objectives: The aim of this study was to investigate the effect of upper back brace with auditory feedback on posture among office workers with neck pain and forward head posture. Study Design: The study design involves prospective, experimental, pre--post single group. Methods: The office workers (males and females aged 25-60 years) were screened on shoulder girdle flexibility test (fingertips > 2 inches [5 cm] apart). Ten subjects (out of 50 screened subjects) meeting the eligibility criteria were selected for the study. The subjects wore the upper back brace with auditory feedback for 6 h in a day (minimum 30 min in continuation) for 2 weeks. Pre- and post-assessments of the neck disability index (NDI), visual analog scale (VAS), craniovertebral angle (CVA), and scapular index (SI) were carried out at the baseline and after 2 weeks, respectively. Results: Postintervention, significant reduction was found in NDI score (P < 0.05, 95% confidence interval (CI) of mean difference (CI): 2.33-8.72 and VAS score (P < 0.05, 95% CI: 0.70-2.89) and significant improvement was found in CVA score (P < 0.05, 95% CI: 0.60-6.59) and SI score (P < 0.05, 95% CI: 0.70-10.01). Conclusion: The results indicate that the upper back brace with auditory feedback improves the FHRSP and reduces neck pain and related disability among office workers. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated that audition used to complement or substitute visual feedback is effective in conveying spatial information, e.g., sighted individuals can understand the curvature of a shape when solely auditory input is provided. Recently we also demonstrated that, in the absence of vision, auditory feedback of body movements can enhance spatial perception in visually impaired adults and children. In the present study, we assessed whether sighted adults can also improve their spatial abilities related to shape recognition with an audio-motor training based on the idea that the coupling of auditory and motor information can further refine the representation of space when vision is missing. Auditory shape recognition was assessed in 22 blindfolded sighted adults with an auditory task requiring participants to identify four shapes by means of the sound conveyed through a set of consecutive loudspeakers embedded on a fixed two-dimensional vertical array. We divided participants into two groups of 11 adults each, performing a training session in two different modalities: active audio-motor training (experimental group) and passive auditory training (control group). The audio-motor training consisted in the reproduction of specific movements with the arm by relying on the sound produced by an auditory source positioned on the wrist of participants. Results showed that sighted individuals improved the recognition of auditory shapes only after active training, suggesting that audio-motor feedback can be an effective tool to enhance spatial representation when visual information is lacking. [ABSTRACT FROM AUTHOR]

Neural interactions between sensorimotor integration mechanisms play critical roles in voice motor control. We investigated how high-definition transcranial direct current stimulation (HD-tDCS) of the left ventral motor cortex modulates neural mechanisms of sensorimotor integration during voice motor control. HD-tDCS was performed during speech vowel production in an altered auditory feedback (AAF) paradigm in response to upward and downward pitch-shift stimuli. In one experiment, two groups received either anodal or cathodal 2 milliamp (mA) HD-tDCS to the left ventral motor cortex while a third group received sham (placebo) stimulation. In a second experiment, two groups received either 1 mA or 2 mA cathodal HD-tDCS to the left ventral motor cortex. Results of the first experiment indicated that the magnitude of vocal compensation was significantly reduced following anodal and cathodal HD-tDCS only in responses to downward pitch-shift AAF stimuli, with stronger effects associated with cathodal HD-tDCS. However, no such effect was observed following sham stimulation. Results of the second experiment indicate that there is not a differential effect of modulation from 1 mA versus 2 mA. Further, these results replicate the directional finding of the first experiment for vocal compensation in response to downward pitch-shift only. These findings suggest that neurostimulation of the left ventral motor cortex modulates sensorimotor mechanisms underlying voice motor control. We speculate that this effect is associated with the increased contribution of feedforward motor mechanisms, leading to reduced compensatory speech responses to AAF. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine whether the precision of verbal feedback affected the accuracy of a standing long jump performance. Sixty-eight female participants (M age=21.44±1.01 years) were randomly assigned to two experimental groups. In total, each subject performed nine jumps at three distances: 50 cm (3 trials), 75 cm (3 trials) and 100 cm (3 trials). Group 2 performed jumps in a reverse order. During the task execution, the study participants received verbal feedback at different levels of precision (no feedback; information that the jump was either: too far, close, or correct; information about the distance in centimetres). The results of statistical analysis indicated that the speed of changes in jump accuracy depended on the precision of verbal feedback. The difference between an actual jump result and a target result increased proportionally with jump length. With a large number of trials, verbal feedback accuracy does not affect significantly the precision of women’s long jump performance. However, when the high accuracy of task performance needs to be obtained quickly, feedback ought to define the exact difference between the target and the actual jump results. The current findings also indicate that providing no feedback does not contribute to improving motor task performance accuracy. [ABSTRACT FROM AUTHOR]

Repetition reduces word duration. Explanations of this process have appealed to audience design, internal production mechanisms, and combinations thereof [e.g. Kahn, J. M., & Arnold, J. E. (2015). Articulatory and lexical repetition effects on durational reduction: Speaker experience vs. common ground. Language, Cognition and Neuroscience, 30, 103–119]. Jacobs, Yiu, Watson, and Dell [2015. Why are repeated words produced with reduced durations? Evidence from inner speech and homophone production. Journal of Memory and Language, 84, 37–48] proposed the auditory feedback hypothesis, which states that speakers must hear a word, produced either by themselves or another speaker, in order for duration reduction on a subsequent production. We conducted a strong test of the auditory feedback hypothesis in two experiments, in which we used masked auditory feedback and whispering to prevent speakers from hearing themselves fully. Both experiments showed that despite limiting the sources of normal auditory feedback, repetition reduction was observed to equal extents in masked and unmasked conditions, suggesting that repetition reduction may be supported by multiple sources, such as somatosensory feedback and feedforward signals, depending on their availability. [ABSTRACT FROM AUTHOR]

In the context of neurorehabilitation, sound is being increasingly applied for facilitating sensorimotor learning. In this study, we aimed to test the potential value of auditory stimulation for improving gait in chronic stroke patients by inducing alterations of the frequency spectra of walking sounds via a sound system that selectively amplifies and equalizes the signal in order to produce distorted auditory feedback. Twenty‐two patients with lower extremity paresis were exposed to real‐time alterations of their footstep sounds while walking. Changes in body perception, emotion, and gait were quantified. Our results suggest that by altering footsteps sounds, several gait parameters can be modified in terms of left–right foot asymmetry. We observed that augmenting low‐frequency bands or amplifying the natural walking sounds led to a reduction in the asymmetry index of stance and stride times, whereas it inverted the asymmetry pattern in heel–ground exerted force. By contrast, augmenting high‐frequency bands led to opposite results. These gait changes might be related to updating of internal forward models, signaling the need for adjustment of the motor system to reduce the perceived discrepancies between predicted–actual sensory feedbacks. Our findings may have the potential to enhance gait awareness in stroke patients and other clinical conditions, supporting gait rehabilitation. [ABSTRACT FROM AUTHOR]

This study investigates whether real-time auditory feedback has a direct behavioural or perceptual effect on novices performing a golf putting task with limited visual feedback. Due to its significant role in the success of a putt, club head speed was selected as the parameter for sonification. Different combinations of synthesisers, timbral modulations, scales, and mappings were developed to examine whether particular sound classes influenced performance. When compared to trials with static pink noise, we found that, despite their vision being limited at impact, participants were able to use different types of sonification to significantly reduce variability in their distance from the target and ball location estimation. These results suggest that concurrent sound can play an important role in reducing variability in behavioural performance and related perceptual estimations. In addition, we found that, when compared to trials with static pink noise, participants were able to use sonification to significantly lower their average impact velocity. In the discussion, we offer some trends and observations relative to the different sound synthesis parameters and their effects on behavioural and perceptual performance. [ABSTRACT FROM AUTHOR]

We replicated and extended previous research on the use of auditory feedback to decrease toe walking exhibited by 3 children with autism. After pretreatment screening analyses suggested that toe walking occurred independent of social consequences, we attached squeakers to the heels of each participants' shoes. The squeakers provided auditory feedback when participants walked appropriately (i.e., with a heel‐to‐toe gait). For all participants, the auditory feedback itself produced increases in appropriate walking. For 1 participant, this feedback was sufficient to reduce toe walking to clinically acceptable levels; however, for 2 other participants, delivery of edible items paired with the auditory feedback was necessary. Intervention effects maintained when the schedule for edible delivery was thinned for all participants. In addition, for 2 participants, effects maintained when the intervention was implemented in a different setting and with a different person with no edibles or a thin schedule of edibles. [ABSTRACT FROM AUTHOR]

The cerebellum has been implicated in the feedforward control of speech production. However, the role of the cerebellum in the feedback control of speech production remains unclear. To address this question, the present event‐related potential study examined the behavioral and neural correlates of auditory feedback control of vocal production in patients with spinocerebellar ataxia (SCA) and healthy controls. All participants were instructed to produce sustained vowels while hearing their voice unexpectedly pitch‐shifted −200 or −500 cents. The behavioral results revealed significantly larger vocal compensations for pitch perturbations in patients with SCA relative to healthy controls. At the cortical level, patients with SCA exhibited significantly smaller cortical P2 responses that were source localized in the right superior temporal gyrus, primary auditory cortex, and supramarginal gyrus than healthy controls. These findings indicate that reduced brain activity in the right temporal and parietal regions are significant neural contributors to abnormal auditory‐motor processing of vocal pitch regulation as a consequence of cerebellar degeneration, which may be related to disrupted reciprocal interactions between the cerebellum and cortical regions that support the top‐down modulation of auditory‐vocal integration. These differences in behavior and cortical activity between healthy controls and patients with SCA demonstrate that the cerebellum is not only essential for feedforward control but also plays a crucial role in the feedback‐based control of speech production. [ABSTRACT FROM AUTHOR]

When we produce speech movements, we also predict the auditory consequences of the movements. We use discrepancies between our predictions and incoming auditory information to modify our future movements (adapt). Although auditory errors are crucial for speech motor learning, not all perceived auditory errors are consequences of our own actions. Therefore, the brain needs to evaluate the relevance of perceived auditory errors. In this study, we examined error assessment processes involved in auditory motor adaptation by systematically manipulating the correspondence between speech motor outputs and their auditory consequences during speaking. Participants (n = 30) produced speech while they received perturbed auditory feedback (e.g., produced "head" but heard a word that sounded like "had"). In one condition, auditory errors were related to participants' productions (task-relevant errors). In another condition, auditory errors were defined by the experimenter and had no correspondence with participants' speech output (task-irrelevant errors). We found that the extent of adaptation and error sensitivity (derived from a state-space model) were greater in the condition with task-relevant auditory errors compared with those in the condition with task-irrelevant auditory errors. Additionally, participants with smaller perceptual targets (derived from a categorical perception task) adapted more to auditory perturbations, and participants with larger perceptual targets adapted less. Similarly, participants with smaller perceptual targets were more sensitive to errors in the condition with task-relevant auditory errors. Together, our results highlight the intricate mechanisms, involving both perception and production systems, that the brain uses to optimally integrate auditory errors for successful speech motor learning. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate auditory feedback to increase the effectiveness of throwing a "right cross." Auditory feedback, implemented by the mixed martial arts coach, was evaluated in multiple baselines across participants design with four mixed martial arts students, two males and two females, 25–54 years old. The target behavior was the percentage of correct steps in the 20‐step task analysis of throwing a right cross. In the auditory feedback procedure, the coach used a handheld clicker and make the clicking sound as a reinforcer each time the participant performed a specific step in the task analysis correctly. This process continued until all steps were performed correctly. The percentage of correct steps of the right cross improved substantially during assessment sessions following the introduction of the auditory feedback and maintained at 90% or more for all participants during follow‐up. Improvements were also noted in the social validity assessment. [ABSTRACT FROM AUTHOR]

We report an experiment that tested the flexibility of sensorimotor learning in sequence production. Nonpianists and pianists learned simple melodies by ear under one of two auditory feedback conditions: one with normal pitch mapping (higher pitches to the right) and one with an inverted (reversed) mapping. After learning, both groups played melodies from memory while experiencing each feedback condition. Both groups exhibited sensorimotor learning and produced fewer errors at test while hearing the feedback used during training as opposed to the alternate feedback condition. However, learning was unstable for pianists who learned melodies with an inverted feedback condition, who produced more errors at test than pianists who learned melodies with normal-pitch mapping. Acquiring musical skill may therefore constrain subsequent sensorimotor flexibility. [ABSTRACT FROM AUTHOR]

Introduction: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for limb motor symptoms in Parkinson's disease (PD); however, its effect on vocal motor function has yielded conflicted and highly variable results. The present study investigated the effects of STN-DBS on the mechanisms of vocal production and motor control.Methods: A total of 10 PD subjects with bilateral STN-DBS implantation were tested with DBS ON and OFF while they performed steady vowel vocalizations and received randomized upward or downward pitch-shift stimuli (±100 cents) in their voice auditory feedback.Results: Data showed that the magnitude of vocal compensation responses to pitch-shift stimuli was significantly attenuated during DBS ON vs. OFF (p = 0.012). This effect was direction-specific and was only observed when subjects raised their voice fundamental frequency (F0) in the opposite direction to downward stimuli (p = 0.019). In addition, we found that voice F0 perturbation (i.e. jitter) was significantly reduced during DBS ON vs. OFF (p = 0.022), and this DBS-induced modulation was positively correlated with the attenuation of vocal compensation responses to downward pitch-shift stimuli (r = +0.57, p = 0.028).Conclusions: These findings provide the first data supporting the role of STN in vocal F0 motor control in response to altered auditory feedback. The DBS-induced attenuation of vocal compensation responses may result from increased inhibitory effects of the subcortical hyperdirect (fronto-subthalamic) pathways on the vocal motor cortex, which can help stabilize voice F0 and ameliorate vocal motor symptoms by impeding PD subjects' abnormal (i.e. overshooting) vocal responses to alterations in the auditory feedback. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the functionality, accuracy, and usability of a novel smart exercise application (SEA). The functionality such as counting lunges, providing task-related auditory feedback, and testing short-term memory was examined while thirteen young adults (six men, age 25.4 ± 8.3 years) performed the lunge exercise with the SEA. The accuracy of logged motion data including angles and accelerations were also tested. Another twenty-five participants (11 men, age 23.2 ± 5.7 years) evaluated the usability of the SEA interest, motivation, convenience, and strength/cognitive benefit via a questionnaire. The SEA assessed the lunge motion correctly, provided auditory feedback, and tested users' short-term memory as required. High correlations (r = 0.90 to 0.99) with low RMSE (4.85° for direction angle, 0.13 to 0.22 m/s² for acceleration) were observed between the sensor output and the reference output. Bland-Altman plot also showed a low discrepancy between each of the two measures. Most participants positively answered all questions about interest (60%), motivation (40%), convenience (80%), strength benefits (92%), and cognitive benefits (88%) of the SEA. The SEA demonstrated accurate kinematic assessment of accelerations and directions, assessed the lunge motion correctly, and created the appropriate auditory feedback on the shortterm memory task. The high rate of positive responses suggested the potential of the application in future use. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the utility of auditory feedback to improve dance movements of children with disabilities. The target behaviors were fundamental dance skills, individualized to each student, and scored using a task analysis to calculate the percentage of correct steps. The results showed that auditory feedback increased the specific dance skill for each young dancer. Although the skills decreased during the second baseline, the skills increased again in the second intervention phase. [ABSTRACT FROM AUTHOR]