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Purpose: The goal of this study was to examine the effects of increases in vocal effort, without changing speech intensity, on respiratory and articulatory kinematics in young adults with typical voices. Method: A total of 10 participants completed a reading task under three speaking conditions: baseline, mild vocal effort, and maximum vocal effort. Respiratory inductance plethysmography bands around the chest and abdomen were used to estimate lung volumes during speech, and sensor coils for electromagnetic articulography were used to transduce articulatory movements, resulting in the following outcome measures: lung volume at speech initiation (LVSI) and at speech termination (LVST), articulatory kinematic vowel space (AKVS) of two points on the tongue dorsum (body and blade), and lip aperture. Results: With increases in vocal effort, and no statistical changes in speech intensity, speakers showed: (a) no statistically significant differences in LVST, (b) statistically significant increases in LVSI, (c) no statistically significant differences in AKVS measures, and (d) statistically significant reductions in lip aperture. Conclusions: Speakers with typical voices exhibited larger lung volumes at speech initiation during increases in vocal effort, paired with reduced lip displacements. To our knowledge, this is the first study to demonstrate evidence that articulatory kinematics are impacted by modulations in vocal effort. However, the mechanisms underlying vocal effort may differ between speakers with and without voice disorders. Thus, future work should examine the relationship between articulatory kinematics, respiratory kinematics, and laryngeal-level changes during vocal effort in speakers with and without voice disorders. Supplemental Material: https://doi.org/10.23641/asha.17065457, Vocal effort is the perceived exertion as experienced by the speaker and not the listener (Banister, 1979; Borg, 1982; Hunter et al., 2020), and previous work implicates both psychological and [...]

Purpose: Unexpected and sustained manipulations of auditory feedback during speech production result in 'reflexive' and 'adaptive' responses, which can shed light on feedback and feedforward auditory-motor control processes, respectively. Persons with Parkinson's disease (PwPD) have shown aberrant reflexive and adaptive responses, but responses appear to differ for control of vocal and articulatory features. However, these responses have not been examined for both voice and articulation in the same speakers and with respect to auditory acuity and functional speech outcomes (speech intelligibility and naturalness). Method: Here, 28 PwPD on their typical dopaminergic medication schedule and 28 age-, sex-, and hearing-matched controls completed tasks yielding reflexive and adaptive responses as well as auditory acuity for both vocal and articulatory features. Results: No group differences were found for any measures of auditory-motor control, conflicting with prior findings in PwPD while off medication. Auditory-motor measures were also compared with listener ratings of speech function: first formant frequency acuity was related to speech intelligibility, whereas adaptive responses to vocal fundamental frequency manipulations were related to speech naturalness. Conclusions: These results support that auditory-motor processes for both voice and articulatory features are intact for PwPD receiving medication. This work is also the first to suggest associations between measures of auditory-motor control and speech intelligibility and naturalness., Over 90% of persons with Parkinson's disease (PwPD) develop the motor speech disorder hypokinetic dysarthria, involving impairments in the respiratory, vocal, and articulatory features of speech (Broadfoot et al., 2019). [...]

Purpose: The purpose of this study was to explore the relationship between feedback and feedforward control of articulation and voice by measuring reflexive and adaptive responses to first formant ([F.sub.1]) and fundamental frequency ([f.sub.o]) perturbations. In addition, perception of [F.sub.1] and [f.sub.o] perturbation was estimated using passive (listening) and active (speaking) just noticeable difference paradigms to assess the relation of auditory acuity to reflexive and adaptive responses. Method: Twenty healthy women produced single words and sustained vowels while the [F.sub.1] or [f.sub.o] of their auditory feedback was suddenly and unpredictably perturbed to assess reflexive responses or gradually and predictably perturbed to assess adaptive responses. Results: Typical speakers' reflexive responses to sudden perturbation of [F.sub.1] were related to their adaptive responses to gradual perturbation of [F.sub.1]. Specifically, speakers with larger reflexive responses to sudden perturbation of [F.sub.1] had larger adaptive responses to gradual perturbation of [F.sub.1]. Furthermore, their reflexive responses to sudden perturbation of [F.sub.1] were associated with their passive auditory acuity to [F.sub.1] such that speakers with better auditory acuity to [F.sub.1] produced larger reflexive responses to sudden perturbations of [F.sub.1]. Typical speakers' adaptive responses to gradual perturbation of [F.sub.1] were not associated with their auditory acuity to [F.sub.1]. Speakers' reflexive and adaptive responses to perturbation of [f.sub.o] were not related, nor were their responses related to either measure of auditory acuity to [f.sub.o]. Conclusion: These findings indicate that there may be disparate feedback and feedforward control mechanisms for articulatory and vocal error correction based on auditory feedback., According to current computational models of speech production, sensorimotor control of articulation and voice is governed by feedback and feedforward control systems (Guenther, 1994; Guenther et al., 2006; Houde & [...]

Purpose: Given the role of auditory perception in voice production, studies have investigated whether impairments in auditory perception may underlie the noted disruptions in speech in Parkinson's disease (PD). Studies of loudness perception in PD show impairments in the perception of self-generated speech, but not external tones. Studies of pitch perception in PD have only examined external tones, but these studies differed in terms of the interstimulus intervals (ISIs) that were used, did not examine the impact of cognition, and report conflicting results. To clarify pitch perception in PD, this work investigated perception of self-generated vocal pitch, controlling for cognition and ISI. Method: A total of 30 individuals with and without PD completed (a) hearing threshold testing, (b) the Montreal Cognitive Assessment, and (c) an adaptive just-noticeabledifference paradigm under two separate ISIs (100 ms and 1,000 ms) to assess acuity to self-generated vocal pitch. Results: There was no significant difference in acuity between individuals with and without PD. Both groups demonstrated significantly worse acuity for longer compared to shorter ISIs. Montreal Cognitive Assessment scores were not a significant predictor of acuity. Conclusions: The results suggest that acuity to self-generated vocal pitch does not differ between individuals with and without PD., Parkinson's disease (PD) is a progressive neurological condition that has an estimated lifetime risk of 1%-2% (Elbaz et al., 2002). In addition to the cardinal motor symptoms of PD (e.g., [...]

Purpose: Gradual and sudden perturbations of vocal fundamental frequency ([f.sub.o]), also known as adaptive and reflexive [f.sub.o] perturbations, are techniques to study the influence of auditory feedback on voice [f.sub.o] control mechanisms. Previous vocal [f.sub.o] perturbations have incorporated varied setup-specific feedback delays and amplifications. Here, we investigated the effects of feedback delays (10-100 ms) and amplifications on both adaptive and reflexive [f.sub.o] perturbation paradigms, encapsulating the variability in equipment-specific delays (3-45 ms) and amplifications utilized in previous experiments. Method: Responses to adaptive and reflexive [f.sub.o] perturbations were recorded in 24 typical speakers for four delay conditions (10, 40, 70, and 100 ms) or three amplification conditions (-10, +5, and +10 dB relative to microphone) in a counterbalanced order. Repeatedmeasures analyses of variance were carried out on the magnitude of [f.sub.o] responses to determine the effect of feedback condition. Results: There was a statistically significant effect of the level of auditory feedback amplification on the response magnitude during adaptive [f.sub.o] perturbations, driven by the difference between +10- and -10-dB amplification conditions (hold phase difference: M = 38.3 cents, SD = 51.2 cents; after-effect phase: M = 66.1 cents, SD = 84.6 cents). No other statistically significant effects of condition were found for either paradigm. Conclusions: Experimental equipment delays below 100 ms in behavioral paradigms do not affect the results of [f.sub.o] perturbation paradigms. As there is no statistically significant difference between the response magnitudes elicited by +5- and +10-dB auditory amplification conditions, this study is a confirmation that an auditory feedback amplification of +5 dB relative to microphone is sufficient to elicit robust compensatory responses for [f.sub.o] perturbation paradigms., Auditory feedback is an important modality that enables fine-tuning of vocalizations during ongoing vocal productions (Lane & Tranel, 1971; Yates, 1963). Its necessity for fluent speech is substantiated by cases [...]

Purpose: Reduced intensity is a hallmark of speech production in Parkinson's disease (PD). Previous work has examined the perception of intensity in PD to explain these speech deficits. This study reports loudness ratings of pure tones by individuals with PD and controls, all with normal thesholds for older adults.Method: Twenty individuals with PD and 23 age- and sex-matched controls rated the loudness of pure tones from 1 (very soft) to 7 (uncomfortably loud). Tones at 500, 750,1000, 2000, and 4000 Hz were presented from 35 to 80 dB HL (or until a rating of 7 was given). A mixed-model analysis of variance was performed on ratings to assess the effects of group, frequency, sound intensity, and ear. Loudness growth slopes were determined for each participant and analyzed by group.Results: The mean loudness growth slopes of the control and PD groups did not significantly differ.Conclusions: No difference was found in loudness growth slopes in response to externally generated tones in PD. This is in contrast with the findings of previous studies of self-generated speech and externally presented speech. The underlying causes for impaired perception and production of loudness in PD require further investigation., Parkinson's disease (PD) is the second most common neurogenerative disorder (Mayeux, 2003; Tanner & Aston, 2000), and it presents with both motor and nonmotor complications (Jankovic, 2008). The lifetime risk [...]

Purpose: The vocal auditory-motor control of individuals with hyperfunctional voice disorders was examined using a sensorimotor adaptation paradigm. Method: Nine individuals with hyperfunctional voice disorders and 9 individuals with typical voices produced sustained vowels over 160 trials in 2 separate conditions: (a) while experiencing gradual upward perturbations in the fundamental frequency ([f.sub.o]) of their auditory feedback (shift-up) and (b) under no auditory perturbation (control). The shift-up condition consisted of 4 ordered (fixed) phases: baseline (no perturbation), ramp (gradual increases in heard [f.sub.o]), hold (a consistently higher heard [f.sub.o]), and after-effect (no perturbation). Adaptive responses were defined as the difference in produced [f.sub.o] during control and shift-up conditions. Results: Adaptive responses were significantly different between groups. Individuals with typical voices generally showed compensatory adaptive responses, with decreased [f.sub.o] during the ramp and hold phases. Conversely, many individuals with hyperfunctional voice disorders instead displayed the opposite effect by following the direction of the perturbation. When [f.sub.o] was experimentally increased, speakers further increased their [f.sub.o]. Conclusion: Results indicate that some individuals diagnosed with hyperfunctional voice disorders have disrupted auditory-motor control, suggesting atypical neurological function. These findings may eventually allow for the development of new interventions for hyperfunctional voice disorders., Hyperfunctional voice disorders are those associated with vocal hyperfunction, inefficient and/ or inappropriate phonatory behaviors. Hyperfunctional voice disorders include the common diagnoses of muscle tension dysphonia (voice disorders in the [...]