Dynamics of the chest wall during speech production: function of the thorax, rib cage, diaphragm, and abdomen

Volitional inspiration is mediated by two independent output channels in the primary motor cortex

The diaphragm is a multifunctional muscle that mediates both autonomic and volitional inspiration. It is critically involved in vocalization, postural stability, and expulsive core-trunk functions, such as coughing, hiccups, and vomiting. In macaque monkeys, we used retrograde transneuronal transport of rabies virus injected into the left hemidiaphragm to identify cortical neurons that have multisynaptic connections with phrenic motoneurons. Our research demonstrates that representation of the diaphragm in the primary motor cortex (M1) is split into two spatially separate and independent sites. No cortico-cortical connections are known to exist between these two sites. One site is located dorsal to the arm representation within the central sulcus and the second site is lateral to the arm. The dual representation of the diaphragm warrants a revision to the somatotopic map of M1. The dorsal diaphragm representation overlaps with trunk and axial musculature. It is ideally situated to coordinate with these muscles during volitional inspiration and in producing intra-abdominal pressure gradients. The lateral site overlaps the origin of M1 projections to a laryngeal muscle, the cricothyroid. This observation suggests that the coordinated control of laryngeal muscles and the diaphragm during vocalization may be achieved, in part, by co-localization of their representations in M1. The neural organization of the two diaphragm sites underlies a new perspective for interpreting functional imaging studies of respiration and/or vocalization. Furthermore, our results provide novel evidence supporting the concept that overlapping output channels within M1 are a prerequisite for the formation of muscle synergies underlying fine motor control.

The effects of attentional focus on speech motor control in adults who stutter with and without social evaluative threat

PURPOSE

We sought to investigate the effects of cued attentional shifts on speechmotor control in adults who stutter (AWS) and adults who do not stutter (ANS) when speaking under low and high social stress conditions.

METHOD

Thirteen AWS' and 10 ANS' lip aperture (LA) and posterior tongue (PT) movements were assessed under a Cued-Internal and Cued-External attentional focus condition with and without social stress induction (i.e. speaking to an audience). Skin conductance levels were used to measure a stress response. Speech motor control was assessed by measuring movement duration and variability of movement for LA and PT using the spatial temporal index (STI).

RESULTS

A significant Group x Condition interaction was found for LA STI. Post-hoc comparisons indicated AWS' LA STI significantly decreased under Cued External Focus conditions during both low and high social stress. No significant Group x Condition interaction was found for PT STI. AWS showed significantly slower tongue movements (PT) across all low and high social stress conditions; however, there was no significant Group x Condition interaction for PT or LA.

DISCUSSION

Findings yield preliminary insights into the role of attentional focus on speech motor control when speaking during high social stress. Theoretical and clinical implications are discussed.

Has Esophageal Speech Returned as an Increasingly Viable Postlaryngectomy Voice and Speech Rehabilitation Option?

PURPOSE

The literature on postlaryngectomy voice and speech rehabilitation is long-standing. Although multiple rehabilitation options have existed over the years, the acquisition and use of esophageal speech (ES) has decreased significantly over the past 40 years. This reduction coincides with the increased application of tracheoesophageal puncture (TEP) voice restoration. The literature suggests that voice acquisition failures observed secondary to TEP may represent a similar phenomenon that led to ES acquisition failures.

METHOD

A comprehensive review of the literature on ES and TEP voice/speech was conducted. Specific attention was directed toward information on ES and TEP speech failures. Information on pharyngoesophageal segment (PES) spasm in the context of ES and TEP voicing failures was of specific importance.

RESULTS

Similarities between voicing failures with both ES and TEP were identified. In order to resolve spasm in TEP speech, proactive efforts to eliminate it were undertaken, and regardless of the method used, voicing improvements were observed. These data suggest that both ES and TEP speech acquisition failures may be related to the same control mechanisms influencing the PES.

CONCLUSIONS

The elimination of PES spasm provides evidence that justifies the reconsideration of ES. Consequently, ES may return as an increasingly viable postlaryngectomy voice and speech rehabilitation option.

Differences of respiratory kinematics in female and male singers - A comparative study using dynamic magnetic resonance imaging

Breath control is an important factor for singing voice production, but pedagogic descriptions of how a beneficial movement pattern should be performed vary widely and the underlying physiological processes are not understood in detail. Differences in respiratory movements during singing might be related to the sex of the singer. To study sex-related differences in respiratory kinematics during phonation, 12 singers (six male and six female) trained in the Western classical singing tradition were imaged with dynamic magnetic resonance imaging. Singers were asked to sustain phonation at five different pitches and loudness conditions, and cross-sectional images of the lung were acquired. In each dynamic image frame the distances between anatomical landmarks were measured to quantify the movements of the respiratory apparatus. No major difference between male and female singers was found for the general respiratory kinematics of the thorax and the diaphragm during sustained phonation. However when compared to sole breathing, male singers significantly increased their thoracic movements for singing. This behavior could not be observed in female singers. The presented data support the hypothesis that professional singers follow sex-specific breathing strategies. This finding may be important in a pedagogical context where the biological sex of singer and student differ and should be further investigated in a larger cohort.

Immediate Effects of Mindfulness Meditation on the Voice

OBJECTIVES

The benefits of mindfulness meditation are well documented. This study evaluated the immediate effects of mindfulness meditation (MM) on the voice and voice user.

STUDY DESIGN

Prospective experimental study.

METHODS

Participants: 19 vocally healthy (VH) individuals, and 26 individuals with common voice disorders (CVD; benign lesions and hyperfunctional muscle tension) deemed stimulable for voice therapy. Exclusionary criteria: prior training or regular meditation practice. Participants recorded speech samples before and after a 11.5-minute prerecorded session of MM.

PRIMARY OUTCOMES

phonatory aerodynamics and participants' self-reported experience of voice.

SECONDARY OUTCOMES

self-reported anxiety, vocal acoustics, speech breathing patterns, and auditory-perceptual outcomes. Baseline self-reported measures of voice (Voice Handicap Index-10 - VHI-10), breathing (Dyspnea Index - DI), stress (Perceived Stress Scale - PSS), and trait mindfulness (Cognitive and Mindfulness Scale - Revised, CAMS-R, Five Facet Mindfulness Questionnaire - FFMQ) were compared between groups.

RESULTS

At baseline, CVD had significantly higher VHI-10 (P< 0.001) and DI (P= 0.0014), and lower trait mindfulness (CAMS-R, P= 0.02). No difference between groups for PSS or FFMQ. Changes postMM: decreased CPP for all-voiced sentences for VH (P= 0.003), decreased mean SPL (P= 0.012) on sustained vowel for VH, increased mean phonatory airflow during sustained vowel for CVD (P = 0.012). VH demonstrated a decrease in CPP on the all-voice sentence, and CVD demonstrated an increase, resulting in a significant between group difference (P= 0.013). Participants reported improvements in voice, emotional and physical states. State anxiety decreased for both groups (= < 0.001). No other objective outcomes reached significance.

CONCLUSIONS

After a brief MM, participants experienced improvement in physical, emotional, and cognitive states, and in their perceptions of their voice. Results indicate that a brief, single session of MM may be beneficial for some, but not sufficient to override habitual voice and speech patterns. Given the benefits of MM, future work should evaluate MM in a standard voice therapy protocol.

Intensive Voice Treatment (Lee Silverman Voice Treatment [LSVT LOUD]) for Children With Down Syndrome: Phase I Outcomes

PURPOSE

This study examined the effects of an intensive voice treatment Lee Silverman Voice Treatment (LSVT LOUD) on children with Down syndrome (DS) and motor speech disorders.

METHOD

A Phase I, multiple baseline, single-subject design with replication across nine participants with DS was used. Single-word intelligibility, acoustic measures of vocal functioning, and parent perceptions of pre- and posttreatment communication function were used as treatment outcome measures.

RESULTS

All participants completed the full dose of LSVT LOUD and showed gains on one or more of the outcome measures. Patterns of posttreatment improvements were not consistent across participants but were more frequently observed on trained maximum performance tasks compared to tasks reflecting generalization of the treatment skillset. Some participants exhibited a stronger response to treatment, whereas others showed a mixed or weaker response. Parents liked the treatment protocol, perceived benefits from intensive intervention, and indicated they would strongly recommend LSVT LOUD to other parents who have children with DS and motor speech disorders.

CONCLUSIONS

These preliminary results show that children with DS tolerated intensive voice treatment without adverse effects and made select meaningful therapeutic gains. The treatment evidence from this study warrants Phase II treatment studies using LSVT LOUD with a larger group of children with DS.

The influence of gravity on respiratory kinematics during phonation measured by dynamic magnetic resonance imaging

Respiratory kinematics are important for the regulation of voice production. Dynamic MRI is an excellent tool to study respiratory motion providing high-resolution cross-sectional images. Unfortunately, in clinical MRI systems images can only be acquired in a horizontal subject position, which does not take into account gravitational effects on the respiratory apparatus. To study the effect of body posture on respiratory kinematics during phonation, 8 singers were examined both in an open-configuration MRI with a rotatable gantry and a conventional horizontal MRI system. During dynamic MRI the subjects sang sustained tones at different pitches in both supine and upright body positions. Sagittal images of the respiratory system were obtained at 1-3 images per second, from which 6 anatomically defined distances were extracted to characterize its movements in the anterior, medium and posterior section of the diaphragm as well as the rip cage (diameter at the height of the 3rd and 5th rip) and the anterior-posterior position of the diaphragm cupola. Regardless of body position, singers maintained their general principles of respiratory kinematics with combined diaphragm and thorax muscle activation for breath support. This was achieved by expanding their chest an additional 20% during inspiration when singing in the supine position but not for sole breathing. The diaphragm was cranially displaced in supine position for both singing and breathing and its motion range increased. These results facilitate a more realistic extrapolation of research data obtained in a supine position.

Deep learning architectures for estimating breathing signal and respiratory parameters from speech recordings

Respiration is an essential and primary mechanism for speech production. We first inhale and then produce speech while exhaling. When we run out of breath, we stop speaking and inhale. Though this process is involuntary, speech production involves a systematic outflow of air during exhalation characterized by linguistic content and prosodic factors of the utterance. Thus speech and respiration are closely related, and modeling this relationship makes sensing respiratory dynamics directly from the speech plausible, however is not well explored. In this article, we conduct a comprehensive study to explore techniques for sensing breathing signal and breathing parameters from speech using deep learning architectures and address the challenges involved in establishing the practical purpose of this technology. Estimating the breathing pattern from the speech would give us information about the respiratory parameters, thus enabling us to understand the respiratory health using one's speech.

Effect of Maximally Relaxed Lying Posture on the Severity of Stuttering in Young Adults Who Stutter

The current study was carried out with the aim of investigating the effect of maximally relaxed lying posture on disfluencies in young adults who stutter. A total of 24 participants (17 males, seven females; mean age = 24.9 ± 6.2 years) with developmental stuttering were a part of the study. The participants were asked to perform spontaneous speaking and reading aloud tasks in standard sitting and maximally relaxed lying postures. The severity of stuttering for the studied postures was estimated by using the Stuttering Severity Instrument. The results on the Stuttering Severity Instrument showed that stuttering parameters improved during the maximally relaxed lying posture compared with the standard sitting position. The results are discussed in the light of motor control concepts. It is concluded that the maximally relaxed lying posture can facilitate improvement in stuttering scores during spontaneous speaking as well as reading aloud in young adults who stutter. Reduced stuttering scores in the maximally relaxed lying posture suggest that speech therapists can position participants in this position while treating people who stutter.

Changes in Intermuscular Coherence as a Function of Age and Phase of Speech Production During an Overt Reading Task

PURPOSE

The authors evaluated changes in intermuscular coherence (IMC) of orofacial and speech breathing muscles across phase of speech production in healthy younger and older adults.

METHOD

Sixty adults (30 younger = M: 26.97 year; 30 older = M: 66.37 year) read aloud a list of 40 words. IMC was evaluated across phase: preparation (300 ms before speech onset), initiation (300 ms after onset), and total execution (entire word).

RESULTS

Orofacial IMC was lowest in the initiation, higher in preparation, and highest for the total execution phase. Chest wall IMC was lowest for the preparation and initiation and highest for the total execution phase. Despite age-related differences in accuracy, neuromuscular modulation for phase was similar between groups.

CONCLUSION

These results expand our knowledge of speech motor control by demonstrating that IMC is sensitive to phase of speech planning and production.

Neuromuscular and biomechanical adjustments of the speech mechanism during modulation of vocal loudness in children with cerebral palsy and dysarthria

ABSTRACChildren with cerebral palsy (CP) are characterized as difficult to understand because of poor articulation and breathy voice quality. This case series describes the subsystems of the speech mechanism (i.e., respiratory, laryngeal, oroarticulatory) in four children with CP and four matched typically developing children (TDC) during the modulation of vocal loudness. TDC used biomechanically efficient strategies among speech subsystems to increase vocal loudness. Children with CP made fewer breathing adjustments but recruited greater chest wall muscle activity and neuromuscular drive for louder productions. These results inform future clinical research and identify speech treatment targets for children with motor speech disorders.

Respiratory kinematics and the regulation of subglottic pressure for phonation of pitch jumps - a dynamic MRI study

The respiratory system is a central part of voice production as it contributes to the generation of subglottic pressure, which has an impact on voice parameters including fundamental frequency and sound pressure level. Both parameters need to be adjusted precisely during complex phonation tasks such as singing. In particular, the underlying functions of the diaphragm and rib cage in relation to the phonation of pitch jumps are not yet understood in detail. This study aims to analyse respiratory movements during phonation of pitch jumps using dynamic MRI of the lungs. Dynamic images of the breathing apparatus of 7 professional singers were acquired in the supine position during phonation of upwards and downwards pitch jumps in a high, medium, and low range of the singer's tessitura. Distances between characteristic anatomical landmarks in the lung were measured from the series of images obtained. During sustained phonation, the diaphragm elevates, and the rib cage is lowered in a monotonic manner. During downward pitch jumps the diaphragm suddenly changed its movement direction and presented with a short inspiratory activation which was predominant in the posterior part and was associated with a shift of the cupola in an anterior direction. The magnitude of this inspiratory movement was greater for jumps that started at higher compared to lower fundamental frequency. In contrast, expiratory movement of the rib cage and anterior diaphragm were simultaneous and continued constantly during the jump. The data underline the theory of a regulation of subglottic pressure via a sudden diaphragm contraction during phonation of pitch jumps downwards, while the rib cage is not involved in short term adaptations. This strengthens the idea of a differentiated control of rib cage and diaphragm as different functional units during singing phonation.

Phonation Demonstrates Goal Dependence Under Unique Vocal Intensity and Aerobic Workload Conditions

Purpose This study investigated whether metabolic respiratory requirements (treadmill workload) affected glottal valving in phonation, based on aerodynamic measures, when a sound pressure level (vocal SPL) is dictated as a target goal. Consistent with a theory of action, we hypothesized that adjustments in glottal valving as measured by laryngeal airway resistance would be dependent upon vocal SPL level, even as workload increased, and loud vocal SPL would interfere more with respiratory homeostasis than spontaneous vocal SPL. Method Thirty-two women enrolled who were ages 18-35 years. A repeated-measures design was used with random assignment of workload and vocal SPL conditions. Aerodynamic and acoustic data were collected during phonation, as were gas volume and concentration data. Analyses were performed with generalized estimating equations. Results Laryngeal airway resistance at a low workload significantly increased when vocal SPL changed from spontaneous to loud. At a loud vocal SPL, laryngeal airway resistance decreased when workload changed from rest to either low or high. Regarding the respiratory system response, minute ventilation increased at a loud vocal SPL when workload changed from rest to either low or high. End-tidal CO₂ increased under low and high workloads relative to rest at loud and spontaneous vocal SPLs. Conclusions Mostly consistent with a theory of action, in which motor control is goal dependent (i.e., vocal SPL targets), speakers can achieve a loud vocal SPL despite increases in workload requirements. In contrast, laryngeal airway resistance stays relatively low when vocal SPL occurs spontaneously, suggesting glottal adjustments are made to improve gas exchange as metabolic respiratory requirements become prioritized. Metabolic respiratory requirements appear to be overcome by the overlay of motor control for voicing when a loud vocal SPL is targeted. The implication of goal-dependent phonation for clinicians is that real-world conditions (i.e., loud vocal SPL) matter in vocal testing and voice therapy.

Experiences of Speaking With Noninvasive Positive Pressure Ventilation: A Qualitative Investigation

Purpose The aim of this study was to describe experiences of speaking with 2 forms of noninvasive positive pressure ventilation (NPPV)-mouthpiece NPPV (M-NPPV) and nasal bilevel positive airway pressure (BPAP)-in people with neuromuscular disorders who depend on NPPV for survival. Method Twelve participants (ages 22-68 years; 10 men, 2 women) with neuromuscular disorders (9 Duchenne muscular dystrophy, 1 Becker muscular dystrophy, 1 postpolio syndrome, and 1 spinal cord injury) took part in semistructured interviews about their speech. All subjects used M-NPPV during the day, and all but 1 used BPAP at night for their ventilation needs. Interviews were audio-recorded, transcribed, and verified. A qualitative descriptive phenomenological approach was used to code and develop themes. Results Three major themes emerged from the interview data: (a) M-NPPV aids speaking (by increasing loudness, utterance duration, clarity, and speaking endurance), (b) M-NPPV interferes with the flow of speaking (due to the need to pause to take a breath, problems with mouthpiece placement, and difficulty in using speech recognition software), and (c) nasal BPAP interferes with speaking (by causing abnormal nasal resonance, muffled speech, mask discomfort, and difficulty in coordinating speaking with ventilator-delivered inspirations). Conclusion These qualitative data from chronic NPPV users suggest that both M-NPPV and nasal BPAP may interfere with speaking but that speech is usually better and speaking is usually easier with M-NPPV. These findings can be explained primarily by the nature of the 2 ventilator delivery systems and their interfaces.

Descriptive Analysis of the Interactive Patterning of the Vocalization Subsystems in Healthy Participants: A Dynamic Systems Perspective

Purpose Normative data for many objective voice measures are routinely used in clinical voice assessment; however, normative data reflect vocal output, but not vocalization process. The underlying physiologic processes of healthy phonation have been shown to be nonlinear and thus are likely different across individuals. Dynamic systems theory postulates that performance behaviors emerge from the nonlinear interplay of multiple physiologic components and that certain patterns are preferred and loosely governed by the interactions of physiology, task, and environment. The purpose of this study was to descriptively characterize the interactive nature of the vocalization subsystem triad in subjects with healthy voices and to determine if differing subgroups could be delineated to better understand how healthy voicing is physiologically generated. Method Respiratory kinematic, aerodynamic, and acoustic formant data were obtained from 29 individuals with healthy voices (21 female and eight male). Multivariate analyses were used to descriptively characterize the interactions among the subsystems that contributed to healthy voicing. Results Group data revealed representative measures of the 3 subsystems to be generally within the boundaries of established normative data. Despite this, 3 distinct clusters were delineated that represented 3 subgroups of individuals with differing subsystem patterning. Seven of the 9 measured variables in this study were found to be significantly different across at least 1 of the 3 subgroups indicating differing physiologic processes across individuals. Conclusion Vocal output in healthy individuals appears to be generated by distinct and preferred physiologic processes that were represented by 3 subgroups indicating that the process of vocalization is different among individuals, but not entirely idiosyncratic. Possibilities for these differences are explored using the framework of dynamic systems theory and the dynamics of emergent behaviors. A revised physiologic model of phonation that accounts for differences within and among the vocalization subsystems is described. Supplemental Material https://doi.org/10.23641/asha.7616462.

Differential Cortical Control of Chest Wall Muscles During Pressure- and Volume-Related Expiratory Tasks and the Effects of Acute Expiratory Threshold Loading

We examined whether or not coherence between chest wall intercostal and oblique muscles changed as a function of lung volume excursion, alveolar pressure, and muscular demand. We also assessed the effects of acute expiratory threshold loading (ETL) on chest wall muscular control. A total of 15 healthy adults (7 males; average age = 28 years) completed maximum performance and ETL tasks. Chest wall surface electromyographic and kinematic recordings were made. Participants also performed a session of acute ETL. We showed that corticomuscular control of the chest wall varied as a function of lung volume excursion and muscular effort. Acute ETL had some effect on respiratory kinematics but not coherence.

Voice Stress Analysis: A New Framework for Voice and Effort in Human Performance

People rely on speech for communication, both in a personal and professional context, and often under different conditions of physical, cognitive and/or emotional load. Since vocalization is entirely integrated within both our central (CNS) and autonomic nervous system (ANS), a mounting number of studies have examined the relationship between voice output and the impact of stress. In the current paper, we will outline the different stages of voice output, i.e., breathing, phonation and resonance in relation to a neurovisceral integrated perspective on stress and human performance. In reviewing the function of these three stages of voice output, we will give an overview of the voice parameters encountered in studies on voice stress analysis (VSA) and review the impact of the different types of physiological, cognitive and/or emotional load. In the section "Discussion," with regard to physical load, a competition for ventilation processes required to speak and those to meet metabolic demand of exercised muscles is described. With regard to cognitive and emotional load, we will present the "Model for Voice and Effort" (MoVE) that comprises the integration of ongoing top-down and bottom-up activity under different types of load and combined patterns of voice output. In the MoVE, it is proposed that the fundamental frequency (F0) values as well as jitter give insight in bottom-up/arousal activity and the effort a subject is capable to generate but that its range and variance are related to ongoing top-down processes and the amount of control a subject can maintain. Within the MoVE, a key-role is given to the anterior cingulate cortex (ACC) which is known to be involved in both the equilibration between bottom-up arousal and top-down regulation and vocal activity. Moreover, the connectivity between the ACC and the nervus vagus (NV) is underlined as an indication of the importance of respiration. Since respiration is the driving force of both stress and voice production, it is hypothesized to be the missing-link in our understanding of the underlying mechanisms of the dynamic between speech and stress.

Effects of the Lung Volume on the Electroglottographic Waveform in Trained Female Singers

OBJECTIVES

To determine if in singing there is an effect of lung volume on the electroglottographic waveform, and if so, how it varies over the voice range.

STUDY DESIGN

Eight trained female singers sang the tune "Frère Jacques" in 18 conditions: three phonetic contexts, three dynamic levels, and high or low lung volume. Conditions were randomized and replicated.

METHODS

The audio and EGG signals were recorded in synchrony with signals tracking respiration and vertical larynx position. The first 10 Fourier descriptors of every EGG cycle were computed. These spectral data were clustered statistically, and the clusters were mapped by color into a voice range profile display, thus visualizing the EGG waveform changes under the influence of f_o and SPL. The rank correlations and effect sizes of the relationships between relative lung volume and several adduction-related EGG wave shape metrics were similarly rendered on a color scale, in voice range profile-style 'voice maps.'

RESULTS

In most subjects, EGG waveforms varied considerably over the voice range. Within subjects, reproducibility was high, not only across the replications, but also across the phonetic contexts. The EGG waveforms were quite individual, as was the nature of the EGG shape variation across the range. EGG metrics were significantly correlated to changes in lung volume, in parts of the range of the song, and in most subjects. However, the effect sizes of the relative lung volume were generally much smaller than the effects of f_o and SPL, and the relationships always varied, even changing polarity from one part of the range to another.

CONCLUSIONS

Most subjects exhibited small, reproducible effects of the relative lung volume on the EGG waveform. Some hypothesized influences of tracheal pull were seen, mostly at the lowest SPLs. The effects were however highly variable, both across the moderately wide f_o-SPL range and across subjects. Different singers may be applying different techniques and compensatory behaviors with changing lung volume. The outcomes emphasize the importance of making observations over a substantial part of the voice range, and not only of phonations sustained at a few fundamental frequencies and sound levels.

Vocalization Subsystem Responses to a Temporarily Induced Unilateral Vocal Fold Paralysis

PURPOSE

The purpose of this study is to quantify the interactions of the 3 vocalization subsystems of respiration, phonation, and resonance before, during, and after a perturbation to the larynx (temporarily induced unilateral vocal fold paralysis) in 10 vocally healthy participants. Using dynamic systems theory as a guide, we hypothesized that data groupings would emerge revealing context-dependent patterns in the relationships of variables representing the 3 vocalization subsystems. We also hypothesized that group data would mask important individual variability important to understanding the relationships among the vocalization subsystems.

METHOD

A perturbation paradigm was used to obtain respiratory kinematic, aerodynamic, and acoustic formant measures from 10 healthy participants (8 women, 2 men) with normal voices. Group and individual data were analyzed to provide a multilevel analysis of the data. A 3-dimensional state space model was constructed to demonstrate the interactive relationships among the 3 subsystems before, during, and after perturbation.

RESULTS

During perturbation, group data revealed that lung volume initiations and terminations were lower, with longer respiratory excursions; airflow rates increased while subglottic pressures were maintained. Acoustic formant measures indicated that the spacing between the upper formants decreased (F3-F5), whereas the spacing between F1 and F2 increased. State space modeling revealed the changing directionality and interactions among the 3 subsystems.

CONCLUSIONS

Group data alone masked important variability necessary to understand the unique relationships among the 3 subsystems. Multilevel analysis permitted a richer understanding of the individual differences in phonatory regulation and permitted subgroup analysis. Dynamic systems theory may be a useful heuristic to model the interactive relationships among vocalization subsystems.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.5913532.

The Impact of Glottal Configuration on Speech Breathing

OBJECTIVE

The purpose of this study was to examine whether changes in respiratory patterns occurred in response to volitional changes in glottal configuration.

METHODS

Twelve vocally healthy participants read a passage while wearing the Inductotrace respiratory inductive plethysmograph, which measures the excursions of the rib cage and abdomen. Participants read the passage 5 times in a typical speaking voice (baseline phase), 10 times in an experimental voice, which was similar to a breathy vocal quality (experimental phase), and 5 times again in a typical speaking voice (return phase). Kinematic estimates of lung volume (LV) initiation, LV termination, and LV excursion were collected for each speech breath.

RESULTS

Participants spoke with larger LV excursions during the experimental phase, characterized by increased LV initiation and decreased LV termination compared with the baseline phase.

CONCLUSION

In response to volitional changes in glottal configuration, healthy individuals spoke with increased LV excursion. They both responded to changes (decreasing LV termination) and planned for more efficient future utterances (increasing LV initiation) during the experimental phase. This study demonstrated that respiratory patterns change in response to changes in glottal configuration; future work will examine these patterns in individuals with voice disorders.

Aerodynamic Patterns in Patients With Voice Disorders: A Retrospective Study

OBJECTIVE

A recently published retrospective chart review of aerodynamic profiles of women with primary muscle tension dysphonia by Gillespie et al (2013) identified various relationships between mean airflow rate (MFR) and estimated subglottal pressure (est-Psub). The current retrospective study expanded the diagnostic categories to include all voice disorders referred for voice therapy. Three research questions were proposed: (1) Are there differences in the MFR and the est-Psub compared with the normal control group? (2) Within the disordered population, are there different variations in the pairing of MFR and est-Psub? (3) If these variations exist, are they diagnosis specific?

METHODS

A retrospective chart review of patients seen for acoustic and aerodynamic voice assessment at the Emory Voice Center between January 1, 2013 and December 31, 2014, were examined for aerodynamic measures of est-Psub and MFR; of these, 192 met the inclusion criteria. Simple t test, two-step cluster analysis, and analysis of variance, as well as Tukey multiple comparisons, were performed using R and SPSS.

RESULTS

Mean est-Psub was significantly greater in the group with voice disorder than in the control group (P value < 0.001). However, no statistical significance was found when comparing the MFR with the control group (P value <0.59). Nine possible pairings of MFR and est-Psub were found. Sufficient evidence was not found to detect significant differences in these pairings across diagnostic groups.

CONCLUSION

With regard to the rate and interrelationships of MFR and est-Psub, the findings of this study are similar to those of Gillespie et al, that is, MFR and est-Psub are not determinate of diagnosis.

The Relationship Between Voice and Breathing in the Assessment and Treatment of Voice Disorders

Coordination between the larynx and lower airways is essential for normal voice production. Dyscoordination may contribute to myriad voice problems. The current study provides an overview of respiratory and laryngeal physiology as it relates to normal and disordered voice production, as well as a review of phonatory aerodynamic assessment practices. Finally, the integration of voice and breathing in common voice therapy programs is explored.

Respiratory kinematic and airflow differences between reflex and voluntary cough in healthy young adults

Background: Cough is a defensive behavior that can be initiated in response to a stimulus in the airway (reflexively), or on command (voluntarily). There is evidence to suggest that physiological differences exist between reflex and voluntary cough; however, the output (mechanistic and airflow) differences between the cough types are not fully understood. Therefore, the aims of this study were to determine the lung volume, respiratory kinematic, and airflow differences between reflex and voluntary cough in healthy young adults.

Methods: Twenty-five participants (14 female; 18–29 years) were recruited for this study. Participants were evaluated using respiratory inductance plethysmography calibrated with spirometry. Experimental procedures included: (1) respiratory calibration, (2) three voluntary sequential cough trials, and (3) three reflex cough trials induced with 200 μM capsaicin.

Results: Lung volume initiation (LVI; p = 0.003) and lung volume excursion (LVE; p < 0.001) were significantly greater for voluntary cough compared to reflex cough. The rib cage and abdomen significantly influenced LVI for voluntary cough (p < 0.001); however, only the rib cage significantly impacted LVI for reflex cough (p < 0.001). LVI significantly influenced peak expiratory flow rate (PEFR) for voluntary cough (p = 0.029), but not reflex cough (p = 0.610).

Discussion: Production of a reflex cough results in significant mechanistic and airflow differences compared to voluntary cough. These findings suggest that detection of a tussigenic stimulus modifies motor aspects of the reflex cough behavior. Further understanding of the differences between reflex and voluntary cough in older adults and in persons with dystussia (cough dysfunction) will be essential to facilitate the development of successful cough treatment paradigms.

The effect of body position on pulmonary function, chest wall motion, and discomfort in young healthy participants

OBJECTIVE

The purpose of this study was to investigate the effect of different recumbent positions on pulmonary function, chest wall motion, and feelings of discomfort in young nonobese healthy volunteers.

METHODS

Twenty healthy volunteers (age, 28.0±1.4 years; height, 167.5±10.1 cm; weight, 62.3±10.2 kg) were studied in the sitting position and in the following 6 recumbent positions: supine, left retroversion at a 45° tilt, left anteversion at a 45° tilt, right retroversion at a 45° tilt, right anteversion at a 45° tilt, and prone. After 5 minutes of a selected position, pulmonary functions, including vital capacity (VC), forced expiratory volume in 1 second, maximal inspiratory and expiratory mouth pressures (MIP and MEP, respectively), and breathing pattern components at the chest wall were assessed. Discomfort was assessed using a modified Borg scale.

RESULTS

When participants changed position from sitting to each of the 6 recumbent positions, forced expiratory volume in 1 second values decreased significantly (P < .05). None of the participants showed changes in the MIP or MEP in any of the 6 recumbent positions. Rib cage motion was restricted in all recumbent positions except supine, left anteversion at a 45° tilt, and prone. In all 6 recumbent positions, discomfort was experienced during the pulmonary tests. However, in the left retroversion at a 45° tilt position, no discomfort was experienced during the MIP and MEP assessments.

CONCLUSION

In young, nonobese, healthy volunteers, recumbent positions caused diminished pulmonary functions and induced feelings of discomfort.

Accuracy of perceptual and acoustic methods for the detection of inspiratory loci in spontaneous speech

The present study investigates the accuracy of perceptually and acoustically determined inspiratory loci in spontaneous speech for the purpose of identifying breath groups. Sixteen participants were asked to talk about simple topics in daily life at a comfortable speaking rate and loudness while connected to a pneumotach and audio microphone. The locations of inspiratory loci were determined on the basis of the aerodynamic signal, which served as a reference for loci identified perceptually and acoustically. Signal detection theory was used to evaluate the accuracy of the methods. The results showed that the greatest accuracy in pause detection was achieved (1) perceptually, on the basis of agreement between at least two of three judges, and (2) acoustically, using a pause duration threshold of 300 ms. In general, the perceptually based method was more accurate than was the acoustically based method. Inconsistencies among perceptually determined, acoustically determined, and aerodynamically determined inspiratory loci for spontaneous speech should be weighed in selecting a method of breath group determination.

Modulation of chest wall intermuscular coherence: effects of lung volume excursion and transcranial direct current stimulation

Chest wall muscle recruitment varies as a function of the breathing task performed. However, the cortical control of the chest wall muscles during different breathing tasks is not known. We studied chest wall intermuscular coherence during various task-related lung volume excursions in 10 healthy adults (34 ± 15 yr; 2 men, 8 women) and determined if transcranial direct current stimulation (tDCS) could modulate chest wall intermuscular coherence during these tasks. Simultaneous assessment of regional intercostal and oblique electromyographic activity was measured while participants performed standardized tidal breathing, speech, maximum phonation, and vital capacity tasks. Lung volume and chest wall kinematics were determined using variable inductance plethysmography. We found that chest wall area of intermuscular coherence was greater during tidal and speech breathing compared with phonation and vital capacity (all P < 0.05) and between tidal breathing compared with speech breathing (P < 0.05). Anodal tDCS increased chest wall area of intermuscular coherence from 0.04 ± 0.09 prestimulation to 0.18 ± 0.19 poststimulation for vital capacity (P < 0.05). Sham tDCS and cathodal tDCS had no effect on coherence during lung volume excursions. Chest wall kinematics were not affected by tDCS. Our findings indicate that lung volume excursions about the midrange of vital capacity elicit a greater area of chest wall intermuscular coherence compared with lung volume excursions spanning the entire range of vital capacity in healthy adults. Our findings also demonstrate that brief tDCS may modulate the cortical control of the chest wall muscles in a stimulation- and lung volume excursion task-dependent manner but does not affect chest wall kinematics in healthy adults.

Aerodynamic profiles of women with muscle tension dysphonia/aphonia

PURPOSE

In this study, the authors aimed to (a) determine whether phonatory airflows and estimated subglottal pressures (est-Psub) for women with primary muscle tension dysphonia/aphonia (MTD/A) differ from those for healthy speakers; (b) identify different aerodynamic profile patterns within the MTD/A subject group; and (c) determine whether results suggest new understanding of pathogenesis in MTD/A.

METHOD

Retrospective review of aerodynamic data collected from 90 women at the time of primary MTD/A diagnosis.

RESULTS

Aerodynamic profiles were significantly different for women with MTD/A as compared with healthy speakers. Five distinct profiles were identified: (a) normal flow, normal est-Psub; (b) high flow, high est-Psub; (c) low flow, normal est-Psub; (d) normal flow, high est-Psub; and (e) high flow, normal est-Psub.

CONCLUSIONS

This study is the first to identify distinct subgroups of aerodynamic profiles in women with MTD/A and to quantitatively identify a clinical phenomenon sometimes described in association with it-"breath holding"-that is shown by low airflow with normal est-Psub. Results were consistent with clinical claims that diverse respiratory and laryngeal functions may underlie phonatory patterns associated with MTD/A. One potential mechanism, based in psychobiological theory, is introduced to explain some of the variability in aerodynamic profiles of women with MTD/A.

Chest Wall Kinematics during Speech Breathing in Tracheoesophageal Speakers

Objectives:

The purpose of the present study was to determine how tracheoesophageal (TE) speakers manipulate the chest wall (rib cage and abdomen) to speak and how respiratory compromise (chronic obstructive pulmonary disease; COPD) and task variables influence those behaviors.

Methods:

The chest wall movements of 11 male TE speakers (5 with COPD and 6 without COPD) were measured during tidal breathing, spontaneous speech, and reading. Repeated-measures multivariate analyses were used to compare breathing behaviors across speech tasks and by respiratory health. Additional repeated-measures multivariate analyses and 1-way analyses of variance were conducted on temporal, aerodynamic, and linguistic measures.

Results:

There was a significant main effect of task and a significant interaction effect of COPD and task on chest wall movements. Rib cage movements varied by task, whereas abdominal movements were as predicted. There was a significant difference in utterance length by task. There were no main effects of COPD on the chest wall and no significant group differences in utterance length, aerodynamic measures, or intelligibility. The TE speakers were generally accurate in inspiring at appropriate linguistic boundaries.

Conclusions:

The results suggest that there is robust control for speech breathing following laryngectomy, but that there is also increased effort within the chest wall. Implications for future research considerations are discussed.

Accuracy of perceptually based and acoustically based inspiratory loci in reading

Investigations of speech often involve the identification of inspiratory loci in continuous recordings of speech. The present study investigates the accuracy of perceptually determined and acoustically determined inspiratory loci. While wearing a circumferentially vented mask connected to a pneumotach, 16 participants read two passages. The perceptually determined and acoustically determined inspiratory loci were compared with the actual loci of inspiration, which were determined aerodynamically. The results showed that (1) agreement across all three judges was the most accurate of the approaches considered here for detecting inspiratory loci based on listening; (2) the most accurate pause duration threshold for detecting inspiratory loci was 250 msec; and (3) the perceptually based breath-group determination was more accurate than the acoustically based determination of pause duration. Inconsistencies among perceptually determined, acoustically determined, and aerodynamically determined inspiratory loci are not negligible and, therefore, need to be considered when researchers design experiments on breath groups in speech.

Breath group analysis for reading and spontaneous speech in healthy adults

AIMS

The breath group can serve as a functional unit to define temporal and fundamental frequency (f0) features in continuous speech. These features of the breath group are determined by the physiologic, linguistic, and cognitive demands of communication. Reading and spontaneous speech are two speaking tasks that vary in these demands and are commonly used to evaluate speech performance for research and clinical applications. The purpose of this study is to examine differences between reading and spontaneous speech in the temporal and f0 aspects of their breath groups.

METHODS

Sixteen participants read two passages and answered six questions while wearing a circumferentially vented mask connected to a pneumotach. The aerodynamic signal was used to identify inspiratory locations. The audio signal was used to analyze task differences in breath group structure, including temporal and f0 components.

RESULTS

The main findings were that spontaneous speech task exhibited significantly more grammatically inappropriate breath group locations and longer breath group duration than did the passage reading task.

CONCLUSION

The task differences in the percentage of grammatically inadequate breath group locations and in breath group duration for healthy adult speakers partly explain the differences in cognitive-linguistic load between the passage reading and spontaneous speech.

Speech breathing in speakers who use an electrolarynx

Speakers who use an electrolarynx following a total laryngectomy no longer require pulmonary support for speech. Subsequently, chest wall movements may be affected; however, chest wall movements in these speakers are not well defined. The purpose of this investigation was to evaluate speech breathing in speakers who use an electrolarynx during speech and reading tasks. Six speakers who use an electrolarynx underwent an evaluation of chest wall kinematics (e.g., chest wall movements, temporal characteristics of chest wall movement), lung volumes, temporal measures of speech, and the interaction of linguistic influences on ventilation. Results of the present study were compared to previous reports in speakers who use an electrolarynx, as well as to previous reports in typical speakers. There were no significant differences in lung volumes used and the general movement of the chest wall by task; however, there were differences of note in the temporal aspects of chest wall configuration when compared to previous reports in both typical speakers and speakers who use an electrolarynx. These differences were related to timing and posturing of the chest wall. The lack of differences in lung volumes and chest wall movements by task indicates that neither reading nor spontaneous speech exerts a greater influence on speech breathing; however, the temporal and posturing results suggest the possibility of a decoupling of the respiratory system from speech following a total laryngectomy and subsequent alaryngeal speech rehabilitation.

LEARNING OUTCOMES

The reader will be able to understand and describe: (1) The primary differences in speech breathing across alaryngeal speech options; (2) how speech breathing specifically differs (i.e., lung volumes and chest wall movements) in speakers who use an electrolarynx; (3) How the coupling of speech and respiration is altered when pulmonary air is no longer used for speech.

Spoken language can have its impact on the respiratory passage

Spoken language, due its chronic impact, could be looked upon as one of the factors for its role, either in prevention or causation of respiratory illnesses. There will be variations in articulatory-aerodynamics and respiratory system dynamics among the spoken languages. Geographic variation of disease patterns and uncertain etiologies of some respiratory illnesses, which occur due to insult to the mucosal barrier or the defense mechanism of the respiratory passage, may be explained by the hypothesis of unhealthy language. Habituation to a particular spoken language could mask the symptoms of phonotrauma. Other respiratory illnesses could initiate from the phonotrauma by spoken language. There exist lacunae in the research of languages. Finding out the healthy language could mean relative freedom from respiratory illnesses. Healthy spoken language could relieve the stress on vocal cords and improve the defense mechanism of the respiratory passage.

Lung volume during swallowing: single bolus swallows in healthy young adults

PURPOSE

This study examined the relationship between swallowing and lung volume initiation in healthy adults during single swallows of boluses differing in volume and consistency. Differences in lung volume according to respiratory phase surrounding the swallow were also assessed.

METHOD

Nine men and 11 women between the ages of 19 and 28 years served as study participants. Lung volume and respiratory phase data were recorded as each participant completed 5 trials each of 10-mL and 20-mL water boluses by cup, and thin and thick paste boluses by spoon, presented in randomized order.

RESULTS

Significant differences in lung volume at swallow initiation were found based on bolus consistency but not on bolus volume. No differences were found for lung volume initiation based on the respiratory phase surrounding the swallow or for the respiratory pattern based on bolus volume or consistency.

CONCLUSION

Findings of this study extend the existing knowledge base regarding the interaction of the swallow and respiratory systems by identifying targeted lung volumes at swallow initiation. In addition to other swallow-related biomechanical events and respiratory phase relationships surrounding a swallow, the lung volume at swallow initiation may be an important consideration when investigating swallow physiology and physiopathy.

Ventilation and speech characteristics during submaximal aerobic exercise

PURPOSE

This study examined alterations in ventilation and speech characteristics as well as perceived dyspnea during submaximal aerobic exercise tasks.

METHOD

Twelve healthy participants completed aerobic exercise-only and simultaneous speaking and aerobic exercise tasks at 50% and 75% of their maximum oxygen consumption (VO(2) max). Measures of ventilation, oxygen consumption, heart rate, perceived dyspnea, syllables per phrase, articulation rate, and inappropriate linguistic pause placements were obtained at baseline and throughout the experimental tasks.

RESULTS

Ventilation was significantly lower during the speaking tasks compared with the nonspeaking tasks. Oxygen consumption, however, did not significantly differ between speaking and nonspeaking tasks. The perception of dyspnea was significantly higher during the speaking tasks compared with the nonspeaking tasks. All speech parameters were significantly altered over time at both task intensities.

CONCLUSIONS

It is speculated that decreased ventilation without a reduction in oxygen consumption implies that utilization of oxygen by the working muscles was increased during the speaking tasks to meet the metabolic needs. A greater ability to utilize oxygen from inspired air is found in individuals who are at higher fitness levels, and therefore these findings may have implications for individuals who must complete simultaneous speech and exercise for occupational purposes (e.g., fitness/military drill instructors, singers performing choreography).

The effects of a total laryngectomy on speech breathing

PURPOSE OF REVIEW

Alaryngeal speech rehabilitation following a total laryngectomy is a multifactorial disorder that includes changes in phonation, respiration, and overall general health. Tracheoesophageal speech is the preferred method of rehabilitation. In this approach, pulmonary air support is diverted from the trachea into the esophagus to generate voicing. Tracheoesophageal speakers must overcome radical upper airway changes, increased resistance in the phonatory source, reduced sensory feedback from the respiratory system, and probable respiratory compromise. This review integrates previous laryngectomy research with recent studies investigating kinematics in tracheoesophageal speakers.

RECENT FINDINGS

Tracheoesophageal speakers are often very intelligible and communicate effectively, but little has been done to investigate the physiological demands of tracheoesophageal speech on speakers. Two recent studies have specifically investigated speech breathing behaviors in tracheoesophageal speakers. Both investigations reported increased effort and differences in speech breathing compared to laryngeal speakers; however, continued research is needed to understand the effects of a total laryngectomy on speech breathing.

SUMMARY

The physiological changes following a laryngectomy, especially in the ability to produce tracheoesophageal speech, are not well known. Rehabilitation for these individuals requires an understanding of the changes in respiration that might influence speech breathing behaviors.

Respiratory and laryngeal function during spontaneous speaking in teachers with voice disorders

PURPOSE

To determine if respiratory and laryngeal function during spontaneous speaking were different for teachers with voice disorders compared with teachers without voice problems.

METHOD

Eighteen teachers, 9 with and 9 without voice disorders, were included in this study. Respiratory function was measured with magnetometry, and laryngeal function was measured with electroglottography during 3 spontaneous speaking tasks: a simulated teaching task at a typical loudness level, a simulated teaching task at an increased loudness level, and a conversational speaking task. Electroglottography measures were also obtained for 3 structured speaking tasks: a paragraph reading task, a sustained vowel, and a maximum phonation time vowel.

RESULTS

Teachers with voice disorders started and ended their breath groups at significantly smaller lung volumes than teachers without voice problems during teaching-related speaking tasks; however, there were no between-group differences in laryngeal measures. Task-related differences were found on several respiratory measures and on one laryngeal measure.

CONCLUSIONS

These findings suggest that teachers with voice disorders used different speech breathing strategies than teachers without voice problems. Implications for clinical management of teachers with voice disorders are discussed.

Relative contributions of the ribcage and abdomen to lung volume displacement during speech production

We tested the hypothesis that the pattern of chest wall configuration during speech production correlates with the pattern of chest wall motion during resting breathing. Twenty-one men (age 40 +/- 8 years) with ankylosing spondylitis and varied degrees of ribcage involvement participated in the study. None of the patients had an obvious speech abnormality. Ribcage and abdominal displacements during quiet breathing and during reading were measured with a respiratory plethysmograph. Measurements were taken in the sitting and standing body positions. In each body position, ribcage or abdominal displacements during quiet breathing correlated with the corresponding chest wall displacements recorded during reading (P < 0.001). In addition, linear regression analysis showed that the slope of the chest wall motion loop during quiet breathing correlated with the ratio of ribcage to abdomen contribution to lung volume displacement during reading (r = 0.78, P < 0.001 for sitting and r = 0.64, P = 0.002 for standing position). The slopes of the regression lines did not differ between the sitting and standing body position (P > 0.05). We conclude that the relative contribution of the ribcage and abdomen to lung volume displacement during speech production correlates with the relative ribcage and abdomen contribution to tidal volume during quiet breathing; our data support the notion that the pattern of chest wall configuration during quiet breathing largely predicts the pattern of ribcage and abdomen displacement during speech.

Physiologic development of tongue-jaw coordination from childhood to adulthood

PURPOSE

This investigation aimed to examine the development of tongue-jaw coordination during speech from childhood to adolescence.

METHOD

Electromagnetic articulography was used to track tongue and jaw motion in 48 children and adults (aged 6-38 years) during productions of /t/ and /k/ embedded in sentences.

RESULTS

The coordinative organization of the tongue and jaw exhibited changes until the age of 8-11 years and continued to undergo refinement into late adolescence. The tongue-tip and tongue-body were observed to develop unique kinematic relations with the jaw. While tongue-tip movement became increasingly synchronized with jaw movement, tongue-body and jaw retained movement independence but developed a more consistent kinematic relation.

CONCLUSION

The present results support the notion that speech motor development is nonuniform, with a refinement period from mid-childhood to late adolescence.

Chest wall motion during speech production in patients with advanced ankylosing spondylitis

PURPOSE

To test the hypothesis that ankylosing spondylitis (AS) alters the pattern of chest wall motion during speech production.

METHOD

The pattern of chest wall motion during speech was measured with respiratory inductive plethysmography in 6 participants with advanced AS (5 men, 1 woman, age 45+/-8 years, Schober test 1.45+/-1.5 cm, Bath Ankylosing Spondylitis Functional Index [BASFI] score 6+/-1.7) and 6 healthy volunteers, matched for age and gender. Measurements were made with participants in the upright seated and upright standing body position.

RESULTS

During reading in the seated and standing body positions, the rib cage wall volume displacements were smaller and abdominal wall volume displacements were larger in participants with AS than in healthy controls. There were no differences in the overall lung volume displacements recorded during the expiratory limb of reading in either body position. In the participants with AS, the rib cage remained near the end-expiratory level in both the seated and standing body position, differing from that for the control group.

CONCLUSION

In individuals with advanced AS, the abdomen is the primary contributor to volume displacement. In the absence of speech impairment in participants with AS, the data show the capacity of the abdomen to compensate for the decreased compliance of the rib cage.

Effects of Vocal Training on Respiratory Kinematics during Singing Tasks

This longitudinal study determined the effects of vocal training (VT) on respiratory kinematics and muscle activity during singing tasks. Four voice students, 3 females and 1 male, were recorded during singing tasks once a semester for 3 consecutive semesters. Respiratory kinematic measures included lung volume, rib cage (RCE) and abdominal excursions (ABE). Surface electromyographic measures included burst duration (BD) and peak amplitude (PA) of the pectoralis major, rectus abdominis and external oblique muscles. Descriptive statistics revealed that RCE and ABE increased from the 1st to the 2nd semester, but decreased from the 2nd to the 3rd semester of VT. Overall, mean BD decreased from the 1st to the 2nd semester and increased from the 2nd to the 3rd semester. Mean PA increased from the 1st to the 2nd semester and decreased from the 2nd to the 3rd semester of VT. RCE and muscle force generation of the above muscles increased as the demand level and the length of the phonatory tasks increased. Interpretation of the results suggests that the respiratory system is highly responsive to VT, after only 3 semesters of training.