Sustained Vowel Production Research Articles

Velopharyngeal Gap Size During Sustained Vowel Production Correlates With Perceptual Ratings of Hypernasality in Connected Speech.

The purpose of this study was to investigate the relationship between perceptual ratings of hypernasality made during connected speech and velopharyngeal (VP) gap size measured in millimeters in the sagittal plane during sustained vowel production using magnetic resonance imaging (MRI). A retrospective cross-sectional analysis was completed. A subgroup of 110 participants from another study with an Mage of 10.1 years presenting for management of VP insufficiency was included. Perceptual ratings of hypernasality during connected speech and measurement of gap size during sustained /i/ production on MRI were performed by raters blinded to the participants' medical and surgical history. There was a moderate-to-strong, positive correlation (r = .61; p < .001) between hypernasality ratings and VP gap size measured on MRI using sustained /i/. The odds of a higher hypernasality rating increased as the gap size increased (odds ratio = 1.34; 95% CI [1.20, 1.49]; p < .001). The predicted probability for hypernasality ratings of none/minimal/mild steadily decreased as the gap size increased indicating that lower ratings of hypernasality were associated with smaller gap sizes. For the rating of "moderate" hypernasality, the predicted probability of the rating steadily increased up to 8 mm and then decreased as the gap size continued to increase. The predicted probability for a hypernasality rating of "severe" consistently increased as the gap size increased. Hypernasality ratings made at the connected speech level were significantly associated with VP gap size as measured during sustained vowel production. These findings suggest sustained vowel production elicited on MRI may adequately characterize VP gap size in the evaluation of VP insufficiency.

Premotor cortex is hypoactive during sustained vowel production in individuals with Parkinson's disease and hypophonia.

Hypophonia is a common feature of Parkinson's disease (PD); however, the contribution of motor cortical activity to reduced phonatory scaling in PD is still not clear. In this study, we employed a sustained vowel production task during functional magnetic resonance imaging to compare brain activity between individuals with PD and hypophonia and an older healthy control (OHC) group. When comparing vowel production versus rest, the PD group showed fewer regions with significant BOLD activity compared to OHCs. Within the motor cortices, both OHC and PD groups showed bilateral activation of the laryngeal/phonatory area (LPA) of the primary motor cortex as well as activation of the supplementary motor area. The OHC group also recruited additional activity in the bilateral trunk motor area and right dorsal premotor cortex (PMd). A voxel-wise comparison of PD and HC groups showed that activity in right PMd was significantly lower in the PD group compared to OHC (p < 0.001, uncorrected). Right PMd activity was positively correlated with maximum phonation time in the PD group and negatively correlated with perceptual severity ratings of loudness and pitch. Our findings suggest that hypoactivation of PMd may be associated with abnormal phonatory control in PD.

Normalization of speech kinematic data for characterizing primary muscle tension dysphonia

Primary muscle tension dysphonia (pMTD) is a voice disorder of unknown etiology in which people have reduced volume and become easily fatigued. The tongue has biomechanical linkage to the laryngeal motor system that affects the voice, suggesting that tongue movement variability might be a marker for this disorder. Previous studies of healthy/disordered speech have reduced individual talker differences in physical vocal tract characteristics via normalization procedures. Here, we obtained tongue movement data for diadochokinetic sequences produced by healthy adult talkers and people with pMTD. We used an electromagnetic articulography system to test three healthy adult talkers and a participant with pMTD. We recorded vertical displacement of the tongue dorsum for sustained /a/ and 30 sec of rapidly repeated /pataka/. Displacement (mm) was scaled relative to each talker’s sustained vowel production, while movement time (msec) was normalized by dividing each /ka/ portion by the corresponding /pataka/ utterance length. The results suggest (1) normalization effectively reduced talker variability in tongue movement displacement and timing, and (2) the talker with pMTD showed markedly higher temporal variability, compared to the control talkers. We are currently testing this putative group difference using additional participants.

Egyptian vowel second formant in isolation and in transition following high-frequency fricatives by NLFC hearing aid in children: how does the pattern compare to typically hearing peers?

BackgroundHigh-frequency consonants form an area of difficulty among children with hearing impairment. Many technological setups have emerged in order to improve their audibility, among them nonlinear frequency compression (NLFC). Therefore, the following study was carried out in order to evaluate change in production of high-frequency fricatives by hearing-impaired children utilizing NLFC hearing aids. This was through spectrographic analysis of F2 onset of transition elicited by fricatives in a prevocalic context, and results were compared to typically developing (TD) children. A change in mid-frequency sounds due to high-frequency compression was also tested through production of sustained vowels in isolation.ResultsA preliminary prospective case-control study involved 9 patients with NLFC hearing aids, evaluated at 1- and at 6-month post-fitting, without receiving speech therapy. Spectrographic analysis of F2 formant onset in [a] and [i] vowels when combined with [s] and [f] fricatives in a CV (consonant-vowel) pattern, presented auditorily and audio-visually, was observed and analyzed. One patient was excluded due to noncompliance in attendance. In the 8 patients who completed the study, very high-frequency level of F2 onset in CV was notable in second versus first evaluation in NLFC group, to the extent of surpassing the typical value in TD control group with [i] vowel. Contrastingly, F2 of sustained vowels in isolation took a trend of a lower value after 6 months of NLFC hearing aid use, as compared to the first evaluation. Consequently, the gap between sustained vowel F2 level in TD and NLFC groups widened.ConclusionMean high-frequency range of F2 onset of transition in CV patterns of voiceless fricatives [s] and [f] with [i] and [a] vowels 6 months after NLFC fitting reflects an enhancement in the frequency range production of these sounds. A shift toward a lower F2 frequency range in sustained mid-frequency vowels, on the other hand, remains to be carefully investigated as a sequel of nonlinear frequency compression in the Egyptian hearing-impaired children.

Valores de nasalancia para vocales, serie numérica y oraciones producidas por adultos hablantes de español chileno

ObjectiveThe present study aimed to establish and compare nasalance scores in Spanish-speaking adults of both genders from Chile during the production of sustained vowels, an automatic speech sample and the reading of sentences. Methods46 adults participated, 25 women and 21 men, aged between 18 and 29 years. All without a history of speech therapy, neurological pathologies, intellectual deficit, hearing loss, syndromes or other pathologies that affect speech production. Adequate velopharyngeal function was determined in vivo through a perceptual evaluation of resonance. Nasalance was determined with the Nasometer, model 6450, during the sustained production of the vowels /a/, /i/ and /u/, an automatic repetition of the number series 1-10 and the reading of six sentences, five with consonants high pressure orals and one with nasal consonants. The comparison between both genders was made with the Mann-Whitney U test. ResultsThe sentence with nasal sounds («Mi mamá me mima») presented the highest percentage of nasalance with 66.36%, followed by the numerical series with 24.61% and the vowel /i/ with 23.57%. Meanwhile, sentences with oral sounds and sustained vowels /a/ and /u/ presented an average nasalance that fluctuated between 10.5% (vowel /u/) and 16.52% (sentence: «Fifi fue feliz»). Finally, a significantly higher average was observed in women for three oral sentences: «Pipo patea la pelota» (P=.044), «Tito tapa tarros» (P=.041), and «Fifi fue feliz» (P=.027). ConclusionThe nasalance values obtained in Chilean adults showed variations according to the speech stimulus and the gender of the speakers.

Tongue position variability in sustained vowels produced by healthy children and young adults with and without a semi-occluded vocal tract: A pilot study

Speech development is a process by which talkers learn, among other things, to coordinate neuromuscular activations of motor units spread across several muscles that effect articulator positioning and movement. This paper presents results from an analysis of tongue position variability during sustained vowel production. Data from two children (7 years 11 months, and 9years 7 months) and two young adults (both 20 years 7 months) are presented. Articulatory data were recorded with a 3D/4D ultrasound system, in two conditions: without a semi-occluded vocal tract (“without straw”) and with a semi-occluded vocal tract (“with straw”). Statistical analyses of tongue position variability revealed a main effect of age, with children showing greater variability than adults. There was no statistically significant main effect of condition, but the main effect of age was driven primarily by the “with straw” condition. We speculate that tongue position variability during sustained vowels may be an index of speech motor control maturity, and that the interaction between age and condition suggests children are less able than adults to rely on learned feed-forward motor programs under conditions of somatosensory perturbation, such as the presence of a straw between the lips.

Electroglottographic and Acoustic Parametrization of Phonatory Quality Provide Voice Profiles of Pathological Speakers

The present study firstly tries to find subgroups of pathological male and female phonation using data from a number of 534 pathological speakers. Secondly, this subgroup classification provides a basis for achieving voice profiles of pathological phonatory quality. Using complementarily orientated electroglottographic and acoustic parametrization of phonatory quality, sustained vowel productions of 267 male and 267 female speakers were considered. In a first step, a clustering technique differentiates three subgroups within each gender on the basis of the EGG- and three subgroups on the basis of the acoustic parameters. In a second step, this subgroup definition allows one to present voice profiles of pathological speakers by combining the parameter means of the electroglottographically determined subgroups with those of the acoustically determined subgroups. The presented voice profiles provide a finer reference basis for the classification of different pathological phonation types as well as for the evaluation of shifts in individual phonatory behavior due to therapy or spontaneous recovery.

A Mandarin Chinese Reading Passage for Eliciting Significant Vocal Range Variations

Purpose There is a lack of standardized Mandarin reading text material that could potentially elicit significant variations in fundamental frequency (F0) and in vocal intensity for clinical voice evaluation. In this study, a phonetically balanced "Three Bears Passage" was developed based on the classical "Goldilocks" story for this purpose. The hypothesis was that the vocal range (F0 range and Intensity range) elicited while reading aloud the passage could be similar to that of the voice range profile (VRP) obtained with sustained vowel production and significantly different from that while reading an existing standard Mandarin passage. Method One hundred twenty young adults (60 men and 60 women, aged 25.22 ± 3.74 years) without vocal pathologies and vocal training participated in the study. Vocal range data, including F0-related measures and intensity-related measures, were obtained with Praat in order to construct VRPs for the sustained /a/ and to construct speech range profiles for passage reading. Results F0 range and intensity range for the new passage were significantly larger than those for the existing Mandarin passage for both male and female participants. In particular, the F0 range for the passage was not significantly different from that of the VRP for male participants. Conclusions These findings suggested that the new passage could allow individuals without vocal training to demonstrate a large vocal range in both F0 and vocal intensity, in a passage reading setting in a relatively short time. Further studies should be pursued with the passage to investigate the vocal range and vocal potential of individuals with voice disorders.

The Effect of Pitch and Loudness Auditory Feedback Perturbations on Vocal Quality During Sustained Phonation

Dysphonia is a reduction in vocal quality that impacts communication and is often an early sign of a voice disorder. There is little information regarding the effects of auditory feedback control of loudness and pitch on voice quality. In this study, we used both loudness-shift and pitch-shift paradigms to study the relationship between auditory feedback control and vocal quality as measured by smoothed cepstral peak prominence (CPPS), which reflects the harmonicity of the voice signal. Experimental, mixed design. We applied 200 ms loudness-shifts (± 0, 3, or 6 dB) and pitch-shifts (± 0, 50, and 100 cents) to auditory feedback during sustained vowel production in 25 healthy adults. We then measured CPPS before and after the loudness-shift or pitch-shift to investigate the effect of changes in auditory feedback on vocal harmonicity. Results showed that, on average, CPPS significantly decreased between the first half of the measured segment and the last half of the segment in the absence of auditory feedback shifts, suggesting that voice quality may be reduced across longer vowels over time. Upward and downward shifts in loudness auditory feedback caused a relative increase in CPPS, indicating an improvement in vocal harmonicity, even in cases when vocal intensity was reduced. Pitch alterations had inconsistent and minimal effects. We propose that there may be a control mechanism for voice quality that increases harmonicity of the voice signal to improve voice audibility (ie, ability to be heard) in the presence of unpredictable variability in voice intensity.

A Study of the Correlation between Phonetic Parameters during Sustained Vowel and Speech Production with Benign Laryngeal Disorders

A Study of the Correlation between Phonetic Parameters during Sustained Vowel and Speech Production with Benign Laryngeal Disorders

Vagus nerve stimulation paired with tones for tinnitus suppression: Effects on voice and hearing.

ObjectiveIn individuals with chronic tinnitus, our interest was to determine whether daily low‐level electrical stimulation of the vagus nerve paired with tones (paired‐VNSt) for tinnitus suppression had any adverse effects on motor‐speech production and physiological acoustics of sustained vowels. Similarly, we were also interested in evaluating for changes in pure‐tone thresholds, word‐recognition performance, and minimum‐masking levels. Both voice and hearing functions were measured repeatedly over a period of 1 year.Study designLongitudinal with repeated‐measures.MethodsDigitized samples of sustained frontal, midline, and back vowels (/e/, /o/, /ah/) were analyzed with computer software to quantify the degree of jitter, shimmer, and harmonic‐to‐noise ratio contained in these waveforms. Pure‐tone thresholds, monosyllabic word‐recognition performance, and MMLs were also evaluated for VNS alterations. Linear‐regression analysis was the benchmark statistic used to document change over time in voice and hearing status from a baseline condition.ResultsMost of the regression functions for the vocal samples and audiometric variables had slope values that were not significantly different from zero. Four of the nine vocal functions showed a significant improvement over time, whereas three of the pure tone regression functions at 2‐4 kHz showed some degree of decline; all changes observed were for the left ear, all were at adjacent frequencies, and all were ipsilateral to the side of VNS. However, mean pure‐tone threshold changes did not exceed 4.29 dB from baseline and therefore, would not be considered clinically significant. In some individuals, larger threshold shifts were observed. No significant regression/slope effects were observed for word‐recognition or MMLs.ConclusionQuantitative voice analysis and assessment of audiometric variables showed minimal if any evidence of adverse effects using paired‐VNSt over a treatment period of 1 year. Therefore, we conclude that paired‐VNSt is a safe tool for tinnitus abatement in humans without significant side effects.Level of evidenceLevel IV.

Auditory Skills as a Predictor of Rater Reliability in the Evaluation of Vocal Quality

To determine whether an association exists between auditory skills and the reliability of judgments of the vocal deviation grade and the degrees of roughness and breathiness and to evaluate whether these skills are predictive of interrater reliability in auditory-perceptual evaluations. The sample consisted of 20 speech-language pathology students without previous training in auditory-perceptual evaluation. The students underwent a basic audiological evaluation and a central auditory processing evaluation. They then participated in two auditory-perceptual evaluation sessions assessing the general grade (GG) and the degrees of roughness and breathiness of 44 samples of sustained vowel production with the presence or absence of dysphonia. For statistical analysis, the intraclass correlation coefficient (ICC) and a beta regression model were used. A difference was found in the average ICCs of the GG parameter between listeners with high and low temporal resolution and binaural interaction skills. Temporal resolution skills and binaural interaction affected the ICC of listeners in the GG evaluation, reducing the likelihood of reliability by 2.8 and 3.6 times, respectively. An association exists between temporal resolution skills and binaural interaction and the reliability of listeners in evaluations of vocal deviation severity. Listeners with low levels of these skills show less reliability in evaluations of the severity of vocal deviation. In addition, temporal resolution and binaural interaction are predictors and explain 42.7% of the variability in the reliability of evaluations of vocal deviation severity.

Auditory feedback control of vocal intensity during speech and sustained-vowel production

Vocal intensity is an important speech component for communicative effectiveness, such as speaking above ambient noise in a loud restaurant, and also for communicative appropriateness, such as speaking quietly in a library. Speakers adjust their vocal intensity using information from their auditory feedback of how loud they perceive their speech. In this study, we were interested in the control of auditory feedback for vocal intensity. Participants repeatedly produced both a simple, sustained-vowel (i.e., “ahhh”) and a short target phrase (i.e., “You know Nina?”) while their voice auditory feedback was briefly perturbed up or down in loudness. We then measured their reflexive intensity response produced quickly after the perturbation to correct for the unexpected change in loudness. In a similar study on pitch perturbations, speakers produced larger reflexive pitch responses as a function of perturbation magnitude in phrase production but did not produce this differential pattern in sustained vowel production (Chen et al., 2007). This result suggests that auditory feedback is more sensitive to changes in suprasegmental features of speech when produced with linguistic intent. In our current study, we are interested in whether this same pattern will be observed for control of vocal intensity.

Mean fundamental frequency in connected speech and sustained vowel with and without a sentence-frame

Introduction: Sustained vowel phonation is a common patient task in the assessment of voice disorders. Free from articulatory influence, it allows for acoustic voice analyses unfeasible for connected speech. Previous research indicates that the fundamental frequency (fo) of a self-chosen vowel is not necessarily representative to mean fo of the same subject’s connected speech.Objective: The purpose was to examine mean fo in text reading and to compare it with sustained vowel phonation with and without a sentence-frame. It was hypothesized, that a short phrase of context embedding the prolonged vowel would affect mean fo of the vowel to be closer to that of text reading.Method: Thirteen vocally healthy women, age 22–27 was audio recorded during three tasks: reading of a standard text, producing an isolated, sustained /a/ and repeating three times a frame sentence with an imbedded /a/ and the third time to sustain the /a/. Mean fo of the three conditions was analyzed by means of the Praat computer program.Results: The isolated vowel condition differed significantly from the mean fo of the sentence-framed one, the latter being closest to mean fo of the reading task. The isolated vowel condition also differed significantly from text reading. The difference in mean fo between sentence-framed vowel and text reading was not significant.Conclusion: Data support that the use of a sentence-frame is helpful to get a client’s fo elicited from sustained vowel production in voice assessments more representative to that of text reading as compared to an isolated vowel.

The effects of age and pitch level on electroglottographic measures during sustained phonation.

The aim of the present study was to use electroglottography (EGG) to explore the effects of age and pitch level on sustained vowel phonation. Thirty female individuals (10 young, 10 middle-aged, and 10 older speakers) without voice disorders or training in singing participated in this study. Eight EGG parameters were measured during sustained vowel production with a high, mid, or low pitch: fundamental frequency, contact quotient, contacting-time quotient, decontacting-time quotient, speed quotient with a midslope criterion (SQ-mid), jitter, shimmer, and the harmonics-to-noise ratio. Age was found to be a significant factor in fundamental frequency, contact quotient, contacting-time quotient, decontacting-time quotient, and SQ-mid. With increasing age, the mean fundamental frequency decreased while the contact quotient increased. The middle-aged and older speakers had more asymmetrical vocal fold vibratory patterns than the young speakers. As for pitch level, the high pitch had a significantly less decontacting-time quotient and greater SQ-mid than low and mid pitches. The lack of significant interaction between age and pitch level indicates that the effects of age and pitch level could be additive. Finally, the discriminant analyses show that contact quotient is an important factor in predicting the age of a voice.

A Study on the Aerodynamic Characteristics of Sustained Vowel and Continuous Speech Production of Female Voice Disorder Patients

A Study on the Aerodynamic Characteristics of Sustained Vowel and Continuous Speech Production of Female Voice Disorder Patients

Mechanisms of voice control related to prosody in autism spectrum disorder and first-degree relatives.

Differences in prosody (e.g., intonation, rhythm) are among the most obvious language‐related impairments in autism spectrum disorder (ASD), and significantly impact communication. Subtle prosodic differences have also been identified in a subset of clinically unaffected first‐degree relatives of individuals with ASD, and may reflect genetic liability to ASD. This study investigated the neural basis of prosodic differences in ASD and first‐degree relatives through analysis of feedforward and feedback control involved in the planning, production, self‐monitoring, and self‐correction of speech by using a pitch‐perturbed auditory feedback paradigm during sustained vowel and speech production. Results revealed larger vocal response magnitudes to pitch‐perturbed auditory feedback across tasks in ASD and ASD parent groups, with differences in sustained vowel production driven by parents who displayed subclinical personality and language features associated with ASD (i.e., broad autism phenotype). Both ASD and ASD parent groups exhibited increased response onset latencies during sustained vowel production, while the ASD parent group exhibited decreased response onset latencies during speech production. Vocal response magnitudes across tasks were associated with prosodic atypicalities in both individuals with ASD and their parents. Exploratory event‐related potential (ERP) analyses in a subgroup of participants during the sustained vowel task revealed reduced P1 ERP amplitudes in the ASD group, with similar trends observed in parents. Overall, results suggest underdeveloped feedforward systems and neural attenuation in detecting audio‐vocal feedback may contribute to ASD‐related prosodic atypicalities. Importantly, results implicate atypical audio‐vocal integration as a marker of genetic risk to ASD, evident in ASD and among clinically unaffected relatives. Autism Res 2019, 12: 1192–1210. © 2019 The Authors. Autism Research published by International Society for Autism Research published by Wiley Periodicals, Inc.Lay SummaryPrevious research has identified atypicalities in prosody (e.g., intonation) in individuals with ASD and a subset of their first‐degree relatives. In order to better understand the mechanisms underlying prosodic differences in ASD, this study examined how individuals with ASD and their parents responded to unexpected differences in what they heard themselves say to modify control of their voice (i.e., audio‐vocal integration). Results suggest that disruptions to audio‐vocal integration in individuals with ASD contribute to ASD‐related prosodic atypicalities, and the more subtle differences observed in parents could reflect underlying genetic liability to ASD.

Cochlear Implant Users’ Vocal Control CorrelatesAcross Tasks

Cochlear implants (CIs) provide access to auditory information that can affect vocal control. For example, previous research shows that, when producing a sustained vowel, CI users will alter the pitch of their voice when the feedback of their own voice is perceived to shift. Although these results can be informative as to how perception and production are linked for CI users, the artificial nature of the task raises questions as to the applicability of the results to real-world vocal productions. To examine how vocal control, when producing sustained vowels, relates to vocal control for more ecologically valid tasks, 10 CI users’ vocal control was measured across two tasks: (1) sustained vowel production, and (2) singing. The results found that vocal control, as measured by the variability of the participants’ fundamental frequency, was significantly correlated when producing sustained vowels and when singing, although variability was significantly greater when singing. This suggests that, despite the artificial nature of sustained vowel production, vocal control on such tasks is related to vocal control for more ecologically valid tasks. However, the results also suggest that vocal control may be overestimated with sustained vowel production tasks.

A Two-Stage Cepstral Analysis Procedure for the Classification of Rough Voices

The objective of this study was to investigate the ability of a two-stage method of cepstral peak identification to effectively discriminate rough vs breathy vs typical voice in sustained vowel productions. It was hypothesized that a dual-stage search for cepstral peak prominences (CPP's) above and below specified quefrency/F0 cutoffs would result in a CPP difference that would be characteristic of the rough, diplophonic voice type. Central one-second portions of sustained vowel /a/ productions were obtained from 90 subjects (rough, breathy, and normophonic voices). All voice samples were analyzed using a a two-stage cepstral analysis process in which a CPPHigh-Low difference value was obtained by identifying cepstral peaks above and below a lower limit for expected F0 (150Hz for females and 90Hz for males), called CPPHigh and CPPLow respectively. The CPPHigh-Low difference value was observed to be a highly significant predictor, with negative values for this parameter characteristic of a dominant subharmonic in the voice signal and the perception of diplophonic, rough voice. Correct classification of rough vs nonrough voice samples was 82.2% (sensitivity 0.80 and specificity 0.833). In the consideration of three group classification (breathy vs. normophonic vs. rough), models incorporating two predictors (the CPP obtained from a single search through a 60 to 300Hz frequency range (CPPDefault) and the CPPHigh-Low difference value) correctly classified 78.88% of the voice samples. Rough, diplophonic voices were consistently observed to have a subharmonic peak that was greater in amplitude than the cepstral peak obtained within the region of the expected F0, resulting in a negative value for the CPPHigh-Low difference. The two-stage cepstral analysis process described herein is visually intuitive from the graphical display of a cepstrum and is a simple extended calculation derived from cepstral analysis procedures that have been recommended as essential in the acoustic description of vocal quality.

Auditory-Motor Control of Vocal Production during Divided Attention: Behavioral and ERP Correlates.

When people hear unexpected perturbations in auditory feedback, they produce rapid compensatory adjustments of their vocal behavior. Recent evidence has shown enhanced vocal compensations and cortical event-related potentials (ERPs) in response to attended pitch feedback perturbations, suggesting that this reflex-like behavior is influenced by selective attention. Less is known, however, about auditory-motor integration for voice control during divided attention. The present cross-modal study investigated the behavioral and ERP correlates of auditory feedback control of vocal pitch production during divided attention. During the production of sustained vowels, 32 young adults were instructed to simultaneously attend to both pitch feedback perturbations they heard and flashing red lights they saw. The presentation rate of the visual stimuli was varied to produce a low, intermediate, and high attentional load. The behavioral results showed that the low-load condition elicited significantly smaller vocal compensations for pitch perturbations than the intermediate-load and high-load conditions. As well, the cortical processing of vocal pitch feedback was also modulated as a function of divided attention. When compared to the low-load and intermediate-load conditions, the high-load condition elicited significantly larger N1 responses and smaller P2 responses to pitch perturbations. These findings provide the first neurobehavioral evidence that divided attention can modulate auditory feedback control of vocal pitch production.