Role Of Auditory Feedback Research Articles

The Role of Auditory Feedback in Voice Control in Normal and Impaired Hearing

The Role of Auditory Feedback in Voice Control in Normal and Impaired Hearing

Тhe role of auditory feedback in voice control with normal and impaired hearing

Control of speech fulfilled by cooperation between feedforward control and feedback control. Feedforward control activates program of articulation, whereas feedback control carries acoustic and sensorimotor information about pronounced utterance. Their complementary speech control function described by the DIVA model, which based on adjustment of auditory and proprioceptive signals relatively to program of articulation in nerve centers. The inconsistency between the sensory information received via feedback and the presentation of the acoustic signal in the auditory nucleus causes corrective commands. Auditory feedback is necessary for the correct development of children’s articulatory skills, i.e. forming feedforward control. For this reason, prelingually deafened adults have significant articulation impairments due to immature articulatory skills. In postlingual deafness, the previously forming feedforward control allows pronounce phonemes successfully. However, in people with sensorineural hearing loss, control of phonation and articulation through the auditory feedback deteriorates, which expressed by an increase of voice intensity, changes in the speech spectral characteristics and instability in frequency and amplitude. Similar speech changes are found in speakers with normal hearing in the presence of noise that masks the speaker’s voice (Lombard effect). In noise, voice intensity increase, spectral characteristics of speech shift to the high-frequency region, and increase the amplitude and speed of articulatory movements (hyperarticulation). This speech reorganization is an adaptation of the speaker’s own voice to background noise, which purpose is to unmask the speech and restore auditory feedback control.

Response patterns to vowel formant perturbations in children.

Auditory feedback is an important component of speech motor control, but its precise role in developing speech is less understood. The role of auditory feedback in development was probed by perturbing the speech of children 4-9 years old. The vowel sound /ɛ/ was shifted to /æ/ in real time and presented to participants as their own auditory feedback. Analyses of the resultant formant magnitude changes in the participants' speech indicated that children compensated and adapted by adjusting their formants to oppose the perturbation. Older and younger children responded to perturbation differently in F1 and F2. The compensatory change in F1 was greater for younger children, whereas the increase in F2 was greater for older children. Adaptation aftereffects were observed in both groups. Exploratory directional analyses in the two-dimensional formant space indicated that older children responded more directly and less variably to the perturbation than younger children, shifting their vowels back toward the vowel sound /ɛ/ to oppose the perturbation. Findings support the hypothesis that auditory feedback integration continues to develop between the ages of 4 and 9 years old such that the differences in the adaptive and compensatory responses arise between younger and older children despite receiving the same auditory feedback perturbation.

Does passive sound attenuation affect responses to pitch-shifted auditory feedback?

The role of auditory feedback in vocal production has mainly been investigated by altered auditory feedback (AAF) in real time. In response, speakers compensate by shifting their speech output in the opposite direction. Current theory suggests this is caused by a mismatch between expected and observed feedback. A methodological issue is the difficulty to fully isolate the speaker's hearing so that only AAF is presented to their ears. As a result, participants may be presented with two simultaneous signals. If this is true, an alternative explanation is that responses to AAF depend on the contrast between the manipulated and the non-manipulated feedback. This hypothesis was tested by varying the passive sound attenuation (PSA). Participants vocalized while auditory feedback was unexpectedly pitch shifted. The feedback was played through three pairs of headphones with varying amounts of PSA. The participants' responses were not affected by the different levels of PSA. This suggests that across all three headphones, PSA is either good enough to make the manipulated feedback dominant, or differences in PSA are too small to affect the contribution of non-manipulated feedback. Overall, the results suggest that it is important to realize that non-manipulated auditory feedback could affect responses to AAF.

Influence of Altered Auditory Feedback on Oral-Nasal Balance in Speakers of Brazilian Portuguese.

Purpose This study explored the role of auditory feedback in the regulation of oral-nasal balance in speakers of Brazilian Portuguese. Method Twenty typical speakers of Brazilian Portuguese (10 male, 10 female) wore a Nasometer headset and headphones while continuously repeating stimuli with oral and nasal sounds. Oral-nasal balance was quantified with nasalance scores. The signals from 2 additional oral and nasal microphones were played back to the participants through the headphones. The relative loudness of the nasal channel in the mix was gradually changed, so that the speakers heard themselves as more or less nasal. Results A repeated-measures analysis of variance of the mean nasalance scores of the stimuli at baseline, minimum, and maximum nasal feedback conditions demonstrated significant effects of nasal feedback condition (p < .0001) and stimuli (p < .0001). Post hoc analyses demonstrated that the mean nasalance scores were lowest for the maximum nasal feedback condition. The scores of the minimum nasal feedback condition were significantly higher than 2 of 3 baseline feedback conditions. The speaking amplitude of the participants did not change between the nasal feedback conditions. Conclusions Increased nasal signal level feedback led to a compensatory adjustment in the opposite direction, confirming that oral-nasal balance is regulated by auditory feedback. However, reduced nasal signal level feedback resulted in a compensatory response that was lower in magnitude. This suggests that, even in Brazilian Portuguese, a language with phonetic and phonological vowel nasalization, decreased nasality was not perceived as critically as increased nasality by the speakers.

The role of auditory feedback in error-detection and correction in first and second language production

Speakers self-correct small variations they hear in their own speech, whether self-produced or experimentally induced perturbations to auditory feedback. In a first language (L1), phonetic categories and therefore auditory expectations are well-established, but in a second language (L2), lack of experience with new categories may interfere with the ability to detect and correct such deviations. We present two companion studies to test how English speakers learning French detect such variations in their auditory feedback in both L1 and L2. In one study, speakers uttered monosyllabic English and French words while simultaneously receiving different levels of masking noise to determine how access to auditory feedback information impacts speakers' ability to make online adjustments to self-produced speech. There was greater acoustic variability at the midpoint of utterances in L2 than in L1, regardless of noise condition, consistent with a differential use of auditory feedback information in the two languages. In a second study, speakers received altered auditory feedback. On one-third of trials, the vowel formants of produced words were shifted up or down, creating the perception of an error. We will compare correction of internally and externally generated error to understand speakers' sensitivity to auditory feedback in native and learned languages.

The role of auditory feedback in learning speech of second languages

Learning to speak requires coordination between auditory and motor systems. Motor programs need to be fine-tuned based on goals and feedback. The motor-tuning process includes establishing the sensory-to-motor transformation (generate motor codes from articulation) and motor-to-sensory transformation (generate predictions for speech control). In this study, we investigated the relations among the three factors (feedback, goals, and predictions) in speech production in the context of second language learning. Adult Mandarin speakers were asked to learn non-native vowels: /o/ and /ɵ/—the former being less similar than the latter to Mandarin vowels, in feedback available or feedback masked conditions. We found no improvement in learning when feedback was masked, suggesting that motor-based prediction could not directly compare with goals for adult second language acquisition. Furthermore, feedback helped to learn only when target sounds are distinct from existing sounds in one’s native speech (competition between prediction and goals is minimal). The results suggest prediction and goals may share a similar representational format, which could yield a competing relation in speech learning. The feedback can conditionally overcome such interference between prediction and goals. The study further probed the functional relations among key components (prediction, goals, and feedback) of sensorimotor integration in speech production and learning.Learning to speak requires coordination between auditory and motor systems. Motor programs need to be fine-tuned based on goals and feedback. The motor-tuning process includes establishing the sensory-to-motor transformation (generate motor codes from articulation) and motor-to-sensory transformation (generate predictions for speech control). In this study, we investigated the relations among the three factors (feedback, goals, and predictions) in speech production in the context of second language learning. Adult Mandarin speakers were asked to learn non-native vowels: /o/ and /ɵ/—the former being less similar than the latter to Mandarin vowels, in feedback available or feedback masked conditions. We found no improvement in learning when feedback was masked, suggesting that motor-based prediction could not directly compare with goals for adult second language acquisition. Furthermore, feedback helped to learn only when target sounds are distinct from existing sounds in one’s native speech (competition be...

Effects of Phantom Electrode Stimulation on Vocal Production in Cochlear Implant Users.

Cochlear implant (CI) users suffer from a range of speech impairments, such as stuttering and vocal control of pitch and intensity. Though little research has focused on the role of auditory feedback in the speech of CI users, these speech impairments could be due in part to limited access to low-frequency cues inherent in CI-mediated listening. Phantom electrode stimulation (PES) represents a novel application of current steering that extends access to low frequencies for CI recipients. It is important to note that PES transmits frequencies below 300 Hz, whereas Baseline does not. The objective of this study was to explore the effects of PES on multiple frequency-related characteristics of voice production. Eight postlingually deafened, adult Advanced Bionics CI users underwent a series of vocal production tests including Tone Repetition, Vowel Sound Production, Passage Reading, and Picture Description. Participants completed all of these tests twice: once with PES and once using their program used for everyday listening (Baseline). An additional test, Automatic Modulation, was included to measure acute effects of PES and was completed only once. This test involved switching between PES and Baseline at specific time intervals in real time as participants read a series of short sentences. Finally, a subjective Vocal Effort measurement was also included. In Tone Repetition, the fundamental frequencies (F0) of tones produced using PES and the size of musical intervals produced using PES were significantly more accurate (closer to the target) compared with Baseline in specific gender, target tone range, and target tone type testing conditions. In the Vowel Sound Production task, vowel formant profiles produced using PES were closer to that of the general population compared with those produced using Baseline. The Passage Reading and Picture Description task results suggest that PES reduces measures of pitch variability (F0 standard deviation and range) in natural speech production. No significant results were found in comparisons of PES and Baseline in the Automatic Modulation task nor in the Vocal Effort task. The findings of this study suggest that usage of PES increases accuracy of pitch matching in repeated sung tones and frequency intervals, possibly due to more accurate F0 representation. The results also suggest that PES partially normalizes the vowel formant profiles of select vowel sounds. PES seems to decrease pitch variability of natural speech and appears to have limited acute effects on natural speech production, though this finding may be due in part to paradigm limitations. On average, subjective ratings of vocal effort were unaffected by the usage of PES versus Baseline.

The Role of Auditory Feedback at Vocalization Onset and Mid-Utterance.

Auditory feedback plays an important role in monitoring and correcting for errors during speech production. Previous research suggests that at vocalization onset, auditory feedback is compared to a sensory prediction generated by the motor system to ensure the desired fundamental frequency (F0) is produced. After vocalization onset, auditory feedback is compared to the most recently perceived F0 in order to stabilize the vocalization. This study aimed to further investigate whether after vocalization onset, auditory feedback is used strictly to stabilize speakers’ F0, or if it is also influenced by the sensory prediction generated by the motor system. Event-related potentials (ERP) were recorded while participants produced vocalizations and heard the F0 of their auditory feedback perturbed suddenly mid-utterance by half a semitone. For half of the vocalizations, at vocalization onset, participants’ F0 was also raised by half a semitone. Thus, half of the perturbations occurred while participants heard their unaltered auditory feedback, and the other half occurred in auditory feedback that had also been perturbed 50 cents at vocalization onset. If after vocalization onset auditory feedback is strictly used to stabilize speakers’ F0, then similarly sized vocal and ERP responses would be expected across all trials, regardless of whether the perturbation occurred while listening to altered or unaltered auditory feedback. Results indicate that the perturbations to the participants’ unaltered auditory feedback resulted in larger vocal and N1 and P2 ERP responses than perturbations to their altered auditory feedback. These results suggest that after vocalization onset auditory feedback is not strictly used to stabilize speakers’ F0, but is also used to ensure the desired F0 is produced.

The role of auditory feedback in music-supported stroke rehabilitation: A single-blinded randomised controlled intervention.

Learning to play musical instruments such as piano was previously shown to benefit post-stroke motor rehabilitation. Previous work hypothesised that the mechanism of this rehabilitation is that patients use auditory feedback to correct their movements and therefore show motor learning. We tested this hypothesis by manipulating the auditory feedback timing in a way that should disrupt such error-based learning. We contrasted a patient group undergoing music-supported therapy on a piano that emits sounds immediately (as in previous studies) with a group whose sounds are presented after a jittered delay. The delay was not noticeable to patients. Thirty-four patients in early stroke rehabilitation with moderate motor impairment and no previous musical background learned to play the piano using simple finger exercises and familiar children's songs. Rehabilitation outcome was not impaired in the jitter group relative to the normal group. Conversely, some clinical tests suggests the jitter group outperformed the normal group. Auditory feedback-based motor learning is not the beneficial mechanism of music-supported therapy. Immediate auditory feedback therapy may be suboptimal. Jittered delay may increase efficacy of the proposed therapy and allow patients to fully benefit from motivational factors of music training. Our study shows a novel way to test hypotheses concerning music training in a single-blinded way, which is an important improvement over existing unblinded tests of music interventions.

Sensorimotor learning in children and adults: Exposure to frequency-altered auditory feedback during speech production

Auditory feedback plays an important role in the acquisition of fluent speech; however, this role may change once speech is acquired and individuals no longer experience persistent developmental changes to the brain and vocal tract. For this reason, we investigated whether the role of auditory feedback in sensorimotor learning differs across children and adult speakers. Participants produced vocalizations while they heard their vocal pitch predictably or unpredictably shifted downward one semitone. The participants’ vocal pitches were measured at the beginning of each vocalization, before auditory feedback was available, to assess the extent to which the deviant auditory feedback modified subsequent speech motor commands. Sensorimotor learning was observed in both children and adults, with participants’ initial vocal pitch increasing following trials where they were exposed to predictable, but not unpredictable, frequency-altered feedback. Participants’ vocal pitch was also measured across each vocalization, to index the extent to which the deviant auditory feedback was used to modify ongoing vocalizations. While both children and adults were found to increase their vocal pitch following predictable and unpredictable changes to their auditory feedback, adults produced larger compensatory responses. The results of the current study demonstrate that both children and adults rapidly integrate information derived from their auditory feedback to modify subsequent speech motor commands. However, these results also demonstrate that children and adults differ in their ability to use auditory feedback to generate compensatory vocal responses during ongoing vocalization. Since vocal variability also differed across the children and adult groups, these results also suggest that compensatory vocal responses to frequency-altered feedback manipulations initiated at vocalization onset may be modulated by vocal variability.

The role of auditory feedback in speech and song.

When singing a melody or producing sentences, we take for granted the fact that the sounds we create (auditory feedback) match the intended consequences of our actions. The importance of these perception/action matches to production is illustrated by the detrimental effects of altered auditory feedback (AAF). Previous research in the domain of music has shown that when AAF leads to asynchronies between perception and action, timing of production is disrupted but accuracy of sequencing is not. On the other hand, AAF manipulations of pitch disrupt sequencing but not timing. Such dissociative effects, as well as other findings, suggest that sensitivity to AAF may be based on hierarchical organization of sequences. In the current research we examined whether similar effects are found for the production of speech, for which syllables rather than pitches may constitute content units. In the first experiment, participants either sang melodies or spoke sequences of nonsense syllables. In the second experiment, the tasks were combined such that participants sang syllable sequences. Production in both experiments was accompanied by either normal, asynchronous, or content altered auditory feedback. Across experiments, effects of AAF on the accuracy of sequencing were similar in speaking and singing tasks, and in all cases reflected the dissociative effects described earlier. For timing of production, however, previous results were only found when participants sang sequences that did not have varying syllabic content. These results suggest that sensitivity to timing exists at multiple hierarchical levels, particularly at the syllable and phonetic levels.

The role of auditory feedback in speech development: A study of compensation strategies for a lip-tube perturbation

The role of auditory feedback in speech development was investigated through a study of compensation strategies for a lip-tube perturbation. Acoustic, articulatory, and perceptual analyses of the vowels /i/, /y/, and /u/ produced by ten 4-year-old French speakers and ten adult French speakers were conducted under two conditions: normal and with a 15-mm-diameter tube (for /y/ and /u/) or a 5-mm-diameter tube (for /i/) inserted between the lips. Ultrasound and acoustic recordings of isolated vowels were made in normal condition before any perturbation (N1), for each of the 20 trials in the perturbed condition (P), and in normal condition after the perturbed trials (N2). Data reveal that adult participants moved their tongue in the P condition more than children subjects, to compensate for F1 and F2 alteration induced by the tube. Except for /y/, the perturbation was generally at least partly compensated during the perturbed trials in adults and children, but children did not show a typical learning effect. Results are analyzed from the perspective of (i) goal specification in speech production in the acoustic and/or somatosensory domain, and (ii) the maturity of representations of the motor apparatus in the brain.

Individual differences in auditory-motor integration revealed by speech fluency manipulations

A role for auditory feedback in maintaining fluency appears less specific than for pitch control, as one example, but delayed auditory feedback (DAF) clearly provides a potent manipulation of fluency. As most speakers are susceptible to DAF, we predicted DAF is particularly suited to identifying individual differences in auditory-motor integration. We conducted a series of studies to probe susceptibility to DAF-induced disfluency in 60 normally fluent speakers during conversation and oral reading. We further contrasted DAF effects on fluency with dual-task effects on fluency. During conversation and reading under DAF (250 ms delay), multivariate cluster classification indicated speakers show high, low, or intermediate susceptibility to disfluency. In contrast, dual-task effects on fluency appeared bimodal with individuals showing high or low susceptibility. DAF susceptibility was not related to dual-task disfluency in 41/60 speakers, but the remaining speakers were disfluent under DAF and dual-task conditions. When the DAF paradigm was extended to adults who stutter, most were classified as highly susceptible. The findings provide compelling evidence that individual differences need to be considered in auditory-motor integration research. Fluency is influenced by both auditory feedback and cognitive factors related to attention, which can inform theories of normal and disordered speech.

The emergence of productive speech and language in Spanish-learning paediatric cochlear implant users

It has been proposed that cochlear implant users may develop robust categorical perception skills, but that they show limited precision in perception. This article explores if a parallel contrast is observable in production, and if, despite acquiring typical linguistic representations, their early words are inconsistent. The participants were eight Spanish-learning deaf children implanted before their second birthday. Two studies examined the transition from babbling to words, and the one-word period. Study 1 found that the participants used the same sound types in babbling and in words, indicating that production is guided by stored motor patterns. No clear evidence of inconsistent production was observed. Study 2 found that in the one-word period CI users develop typical prosodic representations, but that their productions are highly unstable. Results are discussed in terms of the role of auditory feedback for the development of productive language skills.

On the role of auditory feedback in robot-assisted movement training after stroke: review of the literature.

The goal of this paper is to address a topic that is rarely investigated in the literature of technology-assisted motor rehabilitation, that is, the integration of auditory feedback in the rehabilitation device. After a brief introduction on rehabilitation robotics, the main concepts of auditory feedback are presented, together with relevant approaches, techniques, and technologies available in this domain. Current uses of auditory feedback in the context of technology-assisted rehabilitation are then reviewed. In particular, a comparative quantitative analysis over a large corpus of the recent literature suggests that the potential of auditory feedback in rehabilitation systems is currently and largely underexploited. Finally, several scenarios are proposed in which the use of auditory feedback may contribute to overcome some of the main limitations of current rehabilitation systems, in terms of user engagement, development of acute-phase and home rehabilitation devices, learning of more complex motor tasks, and improving activities of daily living.

Musical training and the role of auditory feedback during performance

Recent research has shown that music training enhances music-related sensorimotor associations, such as the relationship between a key press on the keyboard and its associated musical pitch (auditory feedback). Such results suggest that the role of auditory feedback in performance may be based on learned associations that are task specific. Here, results from various studies will be presented that suggest that the real state of affairs is more complex. Several recent studies have shown similar effects of altered auditory feedback during piano performance for pianists and individuals with no piano training. Other recent research suggests dramatic differences between pianists and nonmusicians concerning the influence of auditory feedback on melody switching that suggest greater influence of auditory feedback among nonmusicians than pianists. Taken together, results suggest that musical training refines preexisting sensorimotor associations.

Children's Development of Self-Regulation in Speech Production

Species-specific vocalizations fall into two broad categories: those that emerge during maturation, independent of experience, and those that depend on early life interactions with conspecifics. Human language and the communication systems of a small number of other species, including songbirds, fall into this latter class of vocal learning. Self-monitoring has been assumed to play an important role in the vocal learning of speech and studies demonstrate that perception of your own voice is crucial for both the development and lifelong maintenance of vocalizations in humans and songbirds. Experimental modifications of auditory feedback can also change vocalizations in both humans and songbirds. However, with the exception of large manipulations of timing, no study to date has ever directly examined the use of auditory feedback in speech production under the age of 4. Here we use a real-time formant perturbation task to compare the response of toddlers, children, and adults to altered feedback. Children and adults reacted to this manipulation by changing their vowels in a direction opposite to the perturbation. Surprisingly, toddlers' speech didn't change in response to altered feedback, suggesting that long-held assumptions regarding the role of self-perception in articulatory development need to be reconsidered.

Effects of Auditory Feedback on Movement Time in a Fitts Task

ABSTRACT The purpose of the present experiment was to investigate the role of auditory feedback and its impact on movement time in a standard Fitts task. Feedback was given at the moment of target acquisition. A 2-way analysis of variance found significant differences between feedback groups at all three indexes of difficulty (F(2, 40) = 156.02, p < .001). Results from a mixed-model multivariate analysis of variance for kinematic factors show significant differences in peak velocity and the location of peak velocity when comparing feedback groups. In general, the addition of auditory feedback decreased the task ID by .5.

Comparative study of long-term reduction of high-frequency song syllables in deafened zebra and Bengalese finches: implications for the role of auditory feedback in song maintenance

Auditory feedback is necessary for adult song maintenance in both oscines and psittacines. Although belonging to phylogenically separated orders, deafened adult oscine Bengalese finches and psittacine budgerigars exhibit similarities in certain aspects of song changes. An interesting question is whether these birds share common mechanisms for song maintenance. Therefore, it is important to compare the effects of deafening on adult song patterns among and within orders. Although zebra and Bengalese finches are closely related oscine species, few studies have performed direct, long-term, quantitative comparisons of their songs after deafening because suitable song characteristics have not been identified. Based on our previous findings for Bengalese finch songs, we analyzed zebra finch songs over 9 months after deafening, focusing on changes in the number of syllables categorized according to fundamental frequencies. Deafened zebra finches demonstrated a gradual but significant decrease in high-frequency syllables and a tendency to increase low-frequency syllables, similar to deafened Bengalese finches. Although this change took longer in zebra finches, the altered proportion of syllables eventually stabilized. Results indicated that adult songs show similar aspects after auditory deprivation, and that neural mechanisms involved in the maintenance of high-frequency song syllables, using auditory feedback, may be present in both finches despite species differences.