Modulation of auditory-vocal feedback control due to planned changes in voice fo.

Previous studies have demonstrated that voice fundamental frequency (fo), or pitch, relies on auditory feedback to monitor and correct for errors in production. When voice-pitch auditory feedback is unexpectedly perturbed, individuals typically produce a compensatory change in fo that opposes the direction of the pitch-perturbation. Studies comparing steady vowel vocalizations and speech tasks have demonstrated task-dependent modulation of the compensatory response, but the effects of planning to volitionally change fo during active vocalization have yet to be explored. Ten musicians and ten non-musicians were asked to perform two vocal tasks. Both tasks started off at a conversational fo. In one task, pitch-shifted feedback was presented when the participants were planning to hold fo constant (steady fo), and in the other, feedback was shifted while participants were in the planning stage prior to raising fo (raised fo) from a steady state. Acoustical analyses of fo were performed to measure the peak magnitude and latency of both the compensatory response as well as the voluntary fo change. Results showed that planning to change pitch modulates the mechanisms controlling feedback-based error correction of fo, and musicality affects how individuals incorporate modulations in auditory feedback with the feedforward plans to increase voice fo.

Comparison of volitional opposing and following responses across speakers with different vocal histories.

Research has shown that people who are instructed to volitionally respond to pitch-shifted feedback either produce responses that follow the shift direction with a short latency of 100-200 ms or oppose the shift direction with longer latencies of 300-400 ms. This difference in response latencies prompted a comparison of three groups of vocalists with differing abilities, non-trained English-speaking subjects, non-trained Mandarin-speaking subjects, and trained English-speaking singers. All subjects produced short latency following responses and long latency opposing responses, and in most cases the opposing responses were preceded by a shorter latency following response. Across groups, the magnitudes of the opposing and following responses were largest for the Mandarin speakers. Singers produced the smallest opposing response magnitudes, suggesting differences in the pitch goals of the two groups. Opposing response latencies were longest for the English and Mandarin speaking subjects and shortest for the trained singers, demonstrating that musical training increases the speed of producing the opposing responses. The presence of similar latencies of small following responses preceding larger opposing responses in all groups suggests that the tendency to mimic changes in sounds to which a person is attending are not influenced by vocal training or experience.

Neural Correlates of Vocal Production and Motor Control in Human Heschl's Gyrus.

The present study investigated how pitch frequency, a perceptually relevant aspect of periodicity in natural human vocalizations, is encoded in Heschl's gyrus (HG), and how this information may be used to influence vocal pitch motor control. We recorded local field potentials from multicontact depth electrodes implanted in HG of 14 neurosurgical epilepsy patients as they vocalized vowel sounds and received brief (200 ms) pitch perturbations at 100 Cents in their auditory feedback. Event-related band power responses to vocalizations showed sustained frequency following responses that tracked voice fundamental frequency (F0) and were significantly enhanced in posteromedial HG during speaking compared with when subjects listened to the playback of their own voice. In addition to frequency following responses, a transient response component within the high gamma frequency band (75-150 Hz) was identified. When this response followed the onset of vocalization, the magnitude of the response was the same for the speaking and playback conditions. In contrast, when this response followed a pitch shift, its magnitude was significantly enhanced during speaking compared with playback. We also observed that, in anterolateral HG, the power of high gamma responses to pitch shifts correlated with the magnitude of compensatory vocal responses. These findings demonstrate a functional parcellation of HG with neural activity that encodes pitch in natural human voice, distinguishes between self-generated and passively heard vocalizations, detects discrepancies between the intended and heard vocalization, and contains information about the resulting behavioral vocal compensations in response to auditory feedback pitch perturbations. SIGNIFICANCE STATEMENT: The present study is a significant contribution to our understanding of sensor-motor mechanisms of vocal production and motor control. The findings demonstrate distinct functional parcellation of core and noncore areas within human auditory cortex on Heschl's gyrus that process natural human vocalizations and pitch perturbations in the auditory feedback. In addition, our data provide evidence for distinct roles of high gamma neural oscillations and frequency following responses for processing periodicity in human vocalizations during vocal production and motor control.

The intrinsic resting state voice network in Parkinson's disease.

Over 90 percent of patients with Parkinson's disease experience speech-motor impairment, namely, hypokinetic dysarthria characterized by reduced pitch and loudness. Resting-state functional connectivity analysis of blood oxygen level-dependent functional magnetic resonance imaging is a useful measure of intrinsic neural functioning. We utilized resting-state functional connectivity modeling to analyze the intrinsic connectivity in patients with Parkinson's disease within a vocalization network defined by a previous meta-analysis of speech (Brown et al., 2009). Functional connectivity of this network was assessed in 56 patients with Parkinson's disease and 56 gender-, age-, and movement-matched healthy controls. We also had item 5 and 18 of the UPDRS, and the PDQ-39 Communication subscale available for correlation with the voice network connectivity strength in patients. The within-group analyses of connectivity patterns demonstrated a lack of subcortical-cortical connectivity in patients with Parkinson's disease. At the cortical level, we found robust (homotopic) interhemispheric connectivity but only inconsistent evidence for many intrahemispheric connections. When directly contrasted to the control group, we found a significant reduction of connections between the left thalamus and putamen, and cortical motor areas, as well as reduced right superior temporal gyrus connectivity. Furthermore, most symptom measures correlated with right putamen, left cerebellum, left superior temporal gyrus, right premotor, and left Rolandic operculum connectivity in the voice network. The results reflect the importance of (right) subcortical nodes and the superior temporal gyrus in Parkinson's disease, enhancing our understanding of the neurobiological underpinnings of vocalization impairment in Parkinson's disease.

Connectivity of the subthalamic nucleus and globus pallidus pars interna to regions within the speech network: a meta-analytic connectivity study.

Cortico-basal ganglia connections are involved in a range of behaviors within motor, cognitive, and emotional domains; however, the whole-brain functional connections of individual nuclei are poorly understood in humans. The first aim of this study was to characterize and compare the connectivity of the subthalamic nucleus (STN) and globus pallidus pars interna (GPi) using meta-analytic connectivity modeling. Structure-based activation likelihood estimation meta-analyses were performed for STN and GPi seeds using archived functional imaging coordinates from the BrainMap database. Both regions coactivated with caudate, putamen, thalamus, STN, GPi, and GPe, SMA, IFG, and insula. Contrast analyses also revealed coactivation differences within SMA, IFG, insula, and premotor cortex. The second aim of this study was to examine the degree of overlap between the connectivity maps derived for STN and GPi and a functional activation map representing the speech network. To do this, we examined the intersection of coactivation maps and their respective contrasts (STN > GPi and GPi > STN) with a coordinate-based meta-analysis of speech function. In conjunction with the speech map, both STN and GPi coactivation maps revealed overlap in the anterior insula with GPi map additionally showing overlap in the supplementary motor area (SMA). Among cortical regions activated by speech tasks, STN was found to have stronger connectivity than GPi with regions involved in cognitive linguistic processes (pre-SMA, dorsal anterior insula, and inferior frontal gyrus), while GPi demonstrated stronger connectivity to regions involved in motor speech processes (middle insula, SMA, and premotor cortex).

Left-hemisphere activation is associated with enhanced vocal pitch error detection in musicians with absolute pitch.

The ability to process auditory feedback for vocal pitch control is crucial during speaking and singing. Previous studies have suggested that musicians with absolute pitch (AP) develop specialized left-hemisphere mechanisms for pitch processing. The present study adopted an auditory feedback pitch perturbation paradigm combined with ERP recordings to test the hypothesis whether the neural mechanisms of the left-hemisphere enhance vocal pitch error detection and control in AP musicians compared with relative pitch (RP) musicians and non-musicians (NM). Results showed a stronger N1 response to pitch-shifted voice feedback in the right-hemisphere for both AP and RP musicians compared with the NM group. However, the left-hemisphere P2 component activation was greater in AP and RP musicians compared with NMs and also for the AP compared with RP musicians. The NM group was slower in generating compensatory vocal reactions to feedback pitch perturbation compared with musicians, and they failed to re-adjust their vocal pitch after the feedback perturbation was removed. These findings suggest that in the earlier stages of cortical neural processing, the right hemisphere is more active in musicians for detecting pitch changes in voice feedback. In the later stages, the left-hemisphere is more active during the processing of auditory feedback for vocal motor control and seems to involve specialized mechanisms that facilitate pitch processing in the AP compared with RP musicians. These findings indicate that the left hemisphere mechanisms of AP ability are associated with improved auditory feedback pitch processing during vocal pitch control in tasks such as speaking or singing.

Understanding the mechanisms underlying voluntary responses to pitch-shifted auditory feedback.

Previous research has shown that vocal errors can be simulated using a pitch perturbation technique. Two types of responses are observed when subjects are asked to ignore changes in pitch during a steady vowel production, a compensatory response countering the direction of the perceived change in pitch and a following response in the same direction as the pitch perturbation. The present study investigated the nature of these responses by asking subjects to volitionally change their voice fundamental frequency either in the opposite direction ("opposing" group) or the same direction ("following" group) as the pitch shifts (±100 cents, 1000 ms) presented during the speaker's production of an /a/ vowel. Results showed that voluntary responses that followed the stimulus directions had significantly shorter latencies (150 ms) than opposing responses (360 ms). In addition, prior to the slower voluntary opposing responses, there were short latency involuntary responses that followed the stimulus direction. These following responses may involve mechanisms of imitation or vocal shadowing of acoustical stimuli when subjects are predisposed to respond to a change in frequency of a sound. The slower opposing responses may represent a control strategy that requires monitoring and correcting for errors between the feedback signal and the intended vocal goal.

Effects of sensorimotor voice training on event-related potentials to pitch-shifted auditory feedback.

The pitch perturbation technique is a validated technique that has been used for over 30 years to understand how people control their voice. This technique involves altering a person's voice pitch in real-time while they produce a vowel (commonly, a prolonged /a/ sound). Although post-task changes in the voice have been observed in several studies (e.g., a change in mean fo across the duration of the experiment), the potential for using the pitch perturbation technique as a training tool for voice pitch regulation and/or modification has not been explored. The present study examined changes in event related potentials (ERPs) and voice pitch in three groups of subjects due to altered voice auditory feedback following a brief, four-day training period. Participants in the opposing group were trained to change their voice fo in the opposite direction of a pitch perturbation stimulus. Participants in the following group were trained to change their voice fo in the same direction as the pitch perturbation stimulus. Participants in the non-varying group did not voluntarily change their pitch, but instead were asked to hold their voice constant when they heard pitch perturbations. Results showed that all three types of training affected the ERPs and the voice pitch-shift response from pre-training to post-training (i.e., "hold your voice pitch steady" task; an indicator of voice pitch regulation). Across all training tasks, the N1 and P2 components of the ERPs occurred earlier, and the P2 component of the ERPs occurred with larger amplitude post-training. The voice responses also occurred earlier but with a smaller amplitude following training. These results demonstrate that participation in pitch-shifted auditory feedback tasks even for brief periods of time can modulate the automatic tendency to compensate for alterations in voice pitch feedback and has therapeutic potential.

Auditory-Motor Control of Fundamental Frequency in Vocal Vibrato.

PURPOSE: The purpose of this study was to investigate how classically trained singers use their auditory feedback to control fundamental frequency (fo) during production of vocal vibrato. Two main questions were addressed: (1) Do singers produce reflexive foresponses to sudden perturbation of the fo of their auditory feedback during production of vibrato indicative of feedback control? (2) Do singers produce adaptive foresponses to repeated perturbation of the fo of their auditory feedback during production of vibrato indicative of feedback and feedforward control? In addition, one methodological question was addressed to determine if adaptive fo responses were more precisely assessed with or without an auditory cue for fo during the repeated fo perturbation paradigm. METHOD: Ten classically trained singers produced sustained vowels with vibrato while the fo and harmonics of their auditory feedback were suddenly perturbed by 100 cents to assess reflexive control or repeatedly perturbed by 100 cents to assess adaptive control. Half of the participants completed the repeated perturbation experiment with an auditory cue for fo, and the other half completed the experiment without an auditory cue for fo. Acoustical analyses measured changes in mean fo in response to the auditory feedback perturbations. RESULTS: On average, participants produced compensatory responses to both sudden and repeated perturbation of the fo of their auditory feedback. The magnitude of the responses to repeated perturbations was larger than the responses to sudden perturbations. Responses were also larger in the cued, repeated fo perturbation experiment than in the uncued, repeated fo perturbation experiment. CONCLUSIONS: These findings indicate that classically-trained singers use both feedforward and feedback mechanisms to control their average fo during production of vibrato. When compared to prior studies of singers producing a steady voice, the reflexive fo responses were larger in the current study, which may indicate that the feedback control system is engaged more during production of vibrato.

Deficiency in Re-Orienting of Attention in Adults with Attention-Deficit Hyperactivity Disorder.

Objective: To characterize potential brain indexes of attention deficit hyperactivity disorder (ADHD) in adults. Methods: In an effort to develop objective, laboratory-based tests that can help to establish ADHD diagnosis, the brain indexes of distractibility was investigated in a group of adults. We used event-related brain potentials (ERPs) and performance measures in a forced-choice visual task. Results: Behaviorally aberrant distractibility in the ADHD group was significantly higher. Across three ERP components of distraction: N1 enhancement, P300 (P3a), and Reorienting Negativity (RON) the significant difference between ADHD and matched controls was found in the amplitude of the RON. We used non-parametric randomization tests, enabling us to statistically validated this difference between-group. Conclusions: Our main results of this feasibility study suggest that among other ERP components associated with auditory distraction, the RON response is promising index for a potential biomarker of deficient re-orienting of attention in adults s with ADHD.

Understanding the neural mechanisms involved in sensory control of voice production.

Auditory feedback is important for the control of voice fundamental frequency (F0). In the present study we used neuroimaging to identify regions of the brain responsible for sensory control of the voice. We used a pitch-shift paradigm where subjects respond to an alteration, or shift, of voice pitch auditory feedback with a reflexive change in F0. To determine the neural substrates involved in these audio-vocal responses, subjects underwent fMRI scanning while vocalizing with or without pitch-shifted feedback. The comparison of shifted and unshifted vocalization revealed activation bilaterally in the superior temporal gyrus (STG) in response to the pitch shifted feedback. We hypothesize that the STG activity is related to error detection by auditory error cells located in the superior temporal cortex and efference copy mechanisms whereby this region is responsible for the coding of a mismatch between actual and predicted voice F0.

Opposing and following vocal responses to pitch-shifted auditory feedback: evidence for different mechanisms of voice pitch control.

The present study describes a technique for analysis of vocal responses to auditory feedback pitch perturbations in which individual trials are first sorted according to response direction and then separately averaged in groups of upward or downward responses. In experiment 1, the stimulus direction was predictable (all upward) but magnitude was randomized between +100, +200, or +500 cents (unpredictable). Results showed that pitch-shift stimuli (PSS) of +100 and +200 cents elicited significantly larger opposing (compensatory) responses than +500 cent stimuli, but no such effect was observed for "following" responses. In experiment 2, subjects were tested in three blocks of trials where for the first two, PSS magnitude and direction were predictable (block 1+100 and block 2-100 cents), and in block 3, the magnitude was predictable (±100 cents) but direction was randomized (upward or downward). Results showed there were slightly more opposing than following responses for predictable PSS direction, but randomized directions led to significantly more opposing than following responses. Results suggest that predictability of stimulus direction and magnitude can modulate vocal responses to feedback pitch perturbations. The function and causes of the opposing and following responses are unknown, but there may be two different neural mechanisms involved in their production.

The Effects of Masked and Delayed Auditory Feedback on Fundamental Frequency Modulation in Vocal Vibrato.

PURPOSE: Although relatively precise control over the extent and rate of fundamental frequency (fo) modulation may be needed for optimal production of vibrato, the role of auditory feedback in controlling vibrato is not well understood. Previous studies altered the gain and timing of auditory feedback in singers producing vibrato and showed inconsistent effects on the extent and rate of fo modulation, which may have been related to small sample sizes or limited analyses. Therefore, the purpose of this study was to further investigate whether the gain or timing of auditory feedback impacts control of vibrato in a larger sample of speakers and with advanced statistical analyses. METHOD: Ten classically-trained singers produced sustained vowels with vibrato while their auditory feedback was masked with pink noise or multi-talker babble to reduce the gain of their auditory feedback and while their auditory feedback was delayed by about 200 or 300 milliseconds to alter the timing of their auditory feedback. Acoustical analyses measured changes in the extent and rate of fo modulation in the masked and delayed trials relative to control trials. Bayesian modeling was used to analyze the effects of noise-masked, babble-masked, and delayed auditory feedback on the extent and rate of fo modulation. RESULTS: There was compelling evidence that noise masking increased the extent of fo modulation, and babble masking increased the variability in the rate of fo modulation (ie, jitter of fo modulation). Masked auditory feedback did not affect the average rate of fo modulation. Delayed auditory feedback did not affect the extent, rate, or jitter of fo modulation. CONCLUSIONS: The current study demonstrated that reducing the gain of the auditory feedback with noise masking increased the extent of fo modulation but did not affect the average rate of fo modulation in classically-trained singers producing vibrato. Reducing the gain of the auditory feedback with babble masking and altering the timing of auditory feedback with imposed delays did not affect the average extent or rate of fo modulation. However, babble masking increased the jitter of fo modulation rate, which suggests that modulated auditory feedback may affect the periodicity of fo modulation from one modulation cycle to the next. These findings clarify the role of auditory feedback in controlling vibrato and may inform the current reflex-resonance models of vibrato.

Time-dependent neural processing of auditory feedback during voice pitch error detection.

The neural responses to sensory consequences of a self-produced motor act are suppressed compared with those in response to a similar but externally generated stimulus. Previous studies in the somatosensory and auditory systems have shown that the motor-induced suppression of the sensory mechanisms is sensitive to delays between the motor act and the onset of the stimulus. The present study investigated time-dependent neural processing of auditory feedback in response to self-produced vocalizations. ERPs were recorded in response to normal and pitch-shifted voice auditory feedback during active vocalization and passive listening to the playback of the same vocalizations. The pitch-shifted stimulus was delivered to the subjects' auditory feedback after a randomly chosen time delay between the vocal onset and the stimulus presentation. Results showed that the neural responses to delayed feedback perturbations were significantly larger than those in response to the pitch-shifted stimulus occurring at vocal onset. Active vocalization was shown to enhance neural responsiveness to feedback alterations only for nonzero delays compared with passive listening to the playback. These findings indicated that the neural mechanisms of auditory feedback processing are sensitive to timing between the vocal motor commands and the incoming auditory feedback. Time-dependent neural processing of auditory feedback may be an important feature of the audio-vocal integration system that helps to improve the feedback-based monitoring and control of voice structure through vocal error detection and correction.

Error-dependent modulation of speech-induced auditory suppression for pitch-shifted voice feedback.

BACKGROUND: The motor-driven predictions about expected sensory feedback (efference copies) have been proposed to play an important role in recognition of sensory consequences of self-produced motor actions. In the auditory system, this effect was suggested to result in suppression of sensory neural responses to self-produced voices that are predicted by the efference copies during vocal production in comparison with passive listening to the playback of the identical self-vocalizations. In the present study, event-related potentials (ERPs) were recorded in response to upward pitch shift stimuli (PSS) with five different magnitudes (0, +50, +100, +200 and +400 cents) at voice onset during active vocal production and passive listening to the playback. RESULTS: Results indicated that the suppression of the N1 component during vocal production was largest for unaltered voice feedback (PSS: 0 cents), became smaller as the magnitude of PSS increased to 200 cents, and was almost completely eliminated in response to 400 cents stimuli. CONCLUSIONS: Findings of the present study suggest that the brain utilizes the motor predictions (efference copies) to determine the source of incoming stimuli and maximally suppresses the auditory responses to unaltered feedback of self-vocalizations. The reduction of suppression for 50, 100 and 200 cents and its elimination for 400 cents pitch-shifted voice auditory feedback support the idea that motor-driven suppression of voice feedback leads to distinctly different sensory neural processing of self vs. non-self vocalizations. This characteristic may enable the audio-vocal system to more effectively detect and correct for unexpected errors in the feedback of self-produced voice pitch compared with externally-generated sounds.

Laryngeal electromyographic responses to perturbations in voice pitch auditory feedback.

The present study was conducted to test the hypothesis that intrinsic laryngeal muscles are involved in producing voice fundamental frequency (F(0)) responses to perturbations in voice pitch auditory feedback. Electromyography (EMG) recordings of the cricothyroid and thyroarytenoid muscles were made with hooked-wire electrodes, while subjects sustained vowel phonations at three different voice F(0) levels (conversational, high pitch in head register, and falsetto register) and received randomized pitch shifts (±100 or ±300 cents) in their voice auditory feedback. The median latencies from stimulus onset to the peak in the EMG and voice F(0) responses were 167 and 224 ms, respectively. Among the three different F(0) levels, the falsetto register produced compensatory EMG responses that occurred prior to vocal responses and increased along with rising voice F(0) responses and decreased for falling F(0) responses. For the conversational and high voice levels, the EMG response timing was more variable than in the falsetto voice, and changes in EMG activity with relevance to the vocal responses did not follow the consistent trend observed in the falsetto condition. The data from the falsetto condition suggest that both the cricothyroid and thyroarytenoid muscles are involved in generating the compensatory vocal responses to pitch-shifted voice feedback.

Characterization of Source-Filter Interactions in Vocal Vibrato Using a Neck-Surface Vibration Sensor: A Pilot Study.

PURPOSE: Vocal vibrato is a singing technique that involves periodic modulation of fundamental frequency (fo) and intensity. The physiological sources of modulation within the speech mechanism and the interactions between the laryngeal source and vocal tract filter in vibrato are not fully understood. Therefore, the purpose of this study was to determine if differences in the rate and extent of fo and intensity modulation could be captured using simultaneously recorded signals from a neck-surface vibration sensor and a microphone, which represent features of the source before and after supraglottal vocal tract filtering. METHOD: Nine classically-trained singers produced sustained vowels with vibrato while simultaneous signals were recorded using a vibration sensor and a microphone. Acoustical analyses were performed to measure the rate and extent of fo and intensity modulation for each trial. Paired-samples sign tests were used to analyze differences between the rate and extent of fo and intensity modulation in the vibration sensor and microphone signals. RESULTS: The rate and extent of fo modulation and the extent of intensity modulation were equivalent in the vibration sensor and microphone signals, but the rate of intensity modulation was significantly higher in the microphone signal than in the vibration sensor signal. Larger differences in the rate of intensity modulation were seen with vowels that typically have smaller differences between the first and second formant frequencies. CONCLUSIONS: This study demonstrated that the rate of intensity modulation at the source prior to supraglottal vocal tract filtering, as measured in neck-surface vibration sensor signals, was lower than the rate of intensity modulation after supraglottal vocal tract filtering, as measured in microphone signals. The difference in rate varied based on the vowel. These findings provide further support of the resonance-harmonics interaction in vocal vibrato. Further investigation is warranted to determine if differences in the physiological source(s) of vibrato account for inconsistent relationships between the extent of intensity modulation in neck-surface vibration sensor and microphone signals.

Voice fundamental frequency modulates vocal response to pitch perturbations during English speech.

Previous research has demonstrated task-dependent vocal responses to pitch perturbations during speech production. The present study investigated the effect of voice fundamental frequency (F(0)) on the modulation of vocal responses during English speech. Randomized pitch shifts of +/-100 or 200 cents during speaking were presented to English speakers. Results indicated larger vocal responses and shorter latencies at a high voice F(0) than at a low voice F(0), but no significance differences were observed for stimulus magnitude or direction. These findings suggest that the pitch-shift reflex during speech can be modulated as a function of voice F(0).

Age-related differences in vocal responses to pitch feedback perturbations: a preliminary study.

The present study tested the effect of age on voice fundamental frequency (F(0)) responses to pitch-shifted feedback. Pitch-shift stimuli (-100 cents, 200 ms duration) were presented to 30 native-English speakers: 10 children (7-12 yrs), 10 younger adults (19-21 yrs), and 10 older adults (60-73 yrs). Significantly larger response magnitudes were found in the older group compared to the children and young adult groups, while the longest latencies were associated with the children group as compared to the two adult groups. These findings provide preliminary evidence of an age effect on the modulation of vocal responses to pitch-shifted feedback.

Effect of tonal native language on voice fundamental frequency responses to pitch feedback perturbations during sustained vocalizations.

The purpose of this cross-language study was to examine whether the online control of voice fundamental frequency (F(0)) during vowel phonation is influenced by language experience. Native speakers of Cantonese and Mandarin, both tonal languages spoken in China, participated in the experiments. Subjects were asked to vocalize a vowel sound /u/at their comfortable habitual F(0), during which their voice pitch was unexpectedly shifted (± 50, ± 100, ± 200, or ± 500 cents, 200 ms duration) and fed back instantaneously to them over headphones. The results showed that Cantonese speakers produced significantly smaller responses than Mandarin speakers when the stimulus magnitude varied from 200 to 500 cents. Further, response magnitudes decreased along with the increase in stimulus magnitude in Cantonese speakers, which was not observed in Mandarin speakers. These findings suggest that online control of voice F(0) during vocalization is sensitive to language experience. Further, systematic modulations of vocal responses across stimulus magnitude were observed in Cantonese speakers but not in Mandarin speakers, which indicates that this highly automatic feedback mechanism is sensitive to the specific tonal system of each language.