Hyolaryngeal Kinematics in Primary Muscle Tension Dysphonia Determined by Ultrasound.

OBJECTIVES: The purpose of this study was to determine hyolaryngeal kinematics during voicing in people with primary muscle tension dysphonia (pMTD) compared with healthy speakers, and to investigate the relationships between hyolaryngeal displacement and self-perceived vocal function. METHODS: Twenty-six participants, 13 with pMTD and 13 healthy speakers, were assessed using sonography during sustained vowel phonation and rest. Displacement of the hyoid bone and thyroid cartilage was measured from still frames extracted from ultrasound video recordings, with measures normalized to reflect change from rest during voicing for each participant. Vocal function was determined for all participants through self-perceived speaking effort and the Voice Handicap Index-10. RESULTS: Normalized displacement of the hyoid bone and thyroid cartilage was significantly greater during voicing for participants with pMTD than for the healthy speakers. Weak-to-moderate, nonsignificant relationships between hyoid displacement and vocal function measures were evidenced, whereas moderate-to-strong, significant relationships were found for thyroid displacement and vocal function measures. CONCLUSIONS: Displacement of the hyoid and elevation of the larynx during phonation appear to be prominent features of pMTD that differentiate the disorder from healthy phonatory kinematics. Ultrasound imaging provides a sensitive, reliable, noninvasive, and feasible method for objectively determining hyolaryngeal kinematics and may be useful for differential diagnosis and determination of treatment outcomes in pMTD.

A Conceptual Framework and Treatment Taxonomy for Respiratory Lung Volume Training (RLVT).

OBJECTIVES: The purpose of this study was to describe the theoretical and procedural framework of a novel intervention, Respiratory Lung Volume Training (RLVT), and to implement a standardized treatment taxonomy to operationalize the RLVT treatment paradigm. STUDY DESIGN: This study involved a prospective design with a consensus treatment classification process. METHODS: The RLVT paradigm was developed based on biomechanical constructs governing the interactions of the respiratory and phonatory systems in voice production and principles of motor learning theory. In RLVT, higher levels of lung volume (LV) during speech are trained using multiple speech breathing strategies while providing real-time visual biofeedback with superimposed guidelines for desired LV initiation and termination levels. For people with primary muscle tension dysphonia (MTD), RLVT can capitalize on nonmuscular respiratory forces to increase efficiency of voice production with reduced speaking effort. To define and operationalize the treatment components of RLVT, six investigators with training in RLVT used the Rehabilitation Treatment Specification System to delineate the treatment targets, mechanisms of action, ingredients and dosing through a multistage, consensus decision-making process. RESULTS: The finalized taxonomy for RLVT included four treatment targets, with three addressing the area of Respiratory Function and one addressing Somatosensory Function. For each treatment target, three categories of ingredients were defined: (1) provide opportunities to practice breathing during voicing/speech, (2) provide feedback, and (3) provide volition ingredients. Within each ingredient category, three to seven specific ingredients were ultimately defined to further operationalize RLVT. CONCLUSIONS: The RLVT paradigm is a theoretically driven approach for optimizing speech breathing patterns to increase efficient voice production in people with primary MTD. By applying a standardized, systematic treatment taxonomy system to specify the components of RLVT, future researchers and clinicians can implement RLVT with improved fidelity and consistency to optimize treatment outcomes.

Evaluating Anterior and Posterior Oral Tongue Contributions to Pressure Generation: A Comparison Between Regular and Effortful Saliva Swallows.

PURPOSE: This study determined the contributions of the anterior and posterior tongue regions in tongue pressure generation during regular saliva swallows (SSs) and effortful swallows (ESs) completed under two different instructions. The association between tongue pressure and perceived effort to swallow was also examined. METHOD: Forty healthy adults without swallowing disorders participated in this study, divided into two age groups: 20 younger (Mage = 21.95 years, SD = 4.43) and 20 older (Mage = 70.10 years, SD = 4.30). Simultaneous data acquisition involved submental surface electromyography, tongue manometry, and a visual analog scale across swallowing conditions (SS, ES with tongue emphasis, and ES with pharyngeal squeezing). The main outcome measures were tongue pressure during swallowing and perceived effort to swallow. RESULTS: Overall tongue pressure during ESs with tongue emphasis and with pharyngeal squeezing was greater than that during SSs (R2 = .78, p < .001). Moreover, tongue pressure during the ES with tongue emphasis was greater than that during the ES with pharyngeal squeezing (t = 25.63, p < .001). The posterior tongue region generated more pressure during SSs (R2 = .64, p < .001) and the ES with tongue emphasis (R2 = .55, p < .001) than the anterior tongue. Finally, a positive correlation was found between perceived effort and tongue pressure during swallowing (r = .75, 95% CI [0.72, 0.77]). CONCLUSIONS: Tongue pressure generation was affected by the type of instruction used to elicit ESs, and the posterior tongue showed relatively greater pressure contributions than the anterior tongue for ESs with tongue emphasis and SSs. Furthermore, age-related declines in pressure generation during swallowing were not evidenced in this study, underscoring the ability of healthy older individuals to appropriately modulate lingual pressure during ESs. Last, our results showed that the visual analog scale is a simple tool for rating swallowing effort during ESs, supporting its potential clinical use to train ESs.

Surface Electromyographic Activity of the Masseter Muscle During Regular and Effortful Saliva Swallows: A Preliminary Study.

Biofeedback is a critical component in motor learning of new, complex behaviors such as modifications to swallowing. Surface electromyography (sEMG) is a commonly employed biofeedback tool in swallowing management to assess muscle activity patterns, determine amplitude and duration of swallowing, and train swallowing strategies such as the effortful swallow (EFS) maneuver. The EFS can potentially change multiple physiological components of the swallowing process such as pressure generation and movement of biomechanical structures. The purposes of this study were to determine whether the masseter muscle could differentiate a normal swallow (NS) from an EFS and whether there was a relationship between perceived muscle effort used to swallow and objective measures of muscle activity. Twenty healthy young adults participated in this study. Masseter sEMG peak amplitude and duration were measured across five regular saliva swallows and five effortful saliva swallows. Additionally, participants rated their perceived swallowing effort using a visual analog scale (VAS). Two swallowing conditions, NSs and EFSs were compared with hierarchical models, and repeated measures correlation was used to determine the relationships between the VAS and sEMG peak amplitude. Participants produced swallows with greater masseter sEMG peak amplitude and duration during the EFS. Moreover, a positive correlation was identified between perceived swallowing effort and masseter sEMG peak amplitude. These findings support the potential use of the masseter muscle to differentiate NSs from EFSs and implement the VAS during therapy for tracking patients' performance, particularly in settings with limited access to sEMG.

Hyolaryngeal Movement During Normal and Effortful Swallows Determined During Ultrasonography.

PURPOSE: This study investigated (a) the effects of the effortful swallow under two different instructions (tongue emphasis vs. pharyngeal squeezing) on hyoid displacement and hyoid-larynx approximation, (b) the association between tongue pressure and hyolaryngeal movement during normal swallowing and the effortful swallow produced with tongue emphasis, and (c) age-related differences in hyolaryngeal movement during normal and effortful swallows (tongue emphasis vs. pharyngeal squeezing) in healthy individuals. METHOD: Forty healthy adults (20 younger and 20 older) swallowed their saliva as they normally do (normal swallow) and performed the effortful swallow with tongue emphasis and pharyngeal squeezing. Tongue-to-palate pressure during swallowing was measured using the Iowa Oral Performance Instrument, hyolaryngeal movement was measured using ultrasonography, and submental surface electromyography was used to track swallows. RESULTS: Results revealed differences in hyolaryngeal movement across swallowing types. Both types of effortful swallows showed greater hyolaryngeal movement than normal swallows. Additionally, hyolaryngeal movement was greater during the effortful swallow with tongue emphasis than the effortful swallow with pharyngeal squeezing. Age-related differences were found only in hyoid-larynx approximation during the effortful swallow with tongue emphasis (younger > older adults). Furthermore, moderate positive correlations were identified between tongue pressure and hyolaryngeal movement during normal swallows and the effortful swallow with tongue emphasis. CONCLUSIONS: The findings show that varying instructions of the effortful swallow affect hyolaryngeal movement differently, suggesting that clinicians may need to individualize the effortful swallow instruction according to the physiological impairments of each patient. Additionally, natural age-related changes in swallowing physiology do not seem to affect an individual's ability to perform the effortful swallow or to impact hyolaryngeal movement. Finally, the association between tongue pressure and hyolaryngeal movement during normal swallows and the effortful swallow with tongue emphasis suggests that the tongue plays a critical role in swallowing, priming subsequent swallowing events.

Translating Ultrasound into Clinical Practice for the Assessment of Swallowing and Laryngeal Function: A Speech and Language Pathology-Led Consensus Study.

Ultrasound (US) has an emerging evidence base for the assessment of swallowing and laryngeal function. Accessibility and technological advances support the use of US as a clinical assessment tool; however, there is insufficient evidence to support its translation into clinical practice. This study aimed to establish consensus on the priorities for translation of US into clinical practice for the assessment of swallowing and laryngeal function. Nominal Group Technique (NGT) was used as a formal method of consensus development. Clinicians and academics, all members of an international US working group, were invited to participate in the study. Two NGT meetings were held, where participants silently generated and then shared ideas. Participants anonymously ranked items. Rankings were aggregated before participants re-ranked items in order of priority. Discussions regarding rankings were recorded and transcribed to inform analysis. Member-checking with participants informed the final analysis. Participants (n = 15) were speech and language pathologists, physiotherapists and sonographers representing six countries. Fifteen items were identified and prioritised 1-13 (including two equally ranked items). Reliability, validity and normative data emerged as key areas for research while development of training protocols and engagement with stakeholders were considered vital to progressing US into practice. Analysis revealed common themes that might be addressed together in research, in addition to the ranked priority. A measured approach to the translation of US into clinical practice will enable effective implementation of this tool. Priorities may evolve as clinical and professional contexts shift, but this study provides a framework to advance research and clinical practice in this field.

Isolated and Combined Respiratory Training for Muscle Tension Dysphonia: Preliminary Findings.

PURPOSE: The purpose of this study was to determine the feasibility of altering speech breathing patterns and dysphonia severity through training increased levels of lung volume use during speech. It was hypothesized that respiratory-based training would increase lung volume levels during speech as well as improve acoustic voice measures, and that the addition of laryngeal-based treatment would further improve voice acoustics by treatment completion. METHOD: A multiple baseline, single subject design was replicated over six participants with primary muscle tension dysphonia as a preliminary investigation of novel respiratory treatment methods. Following four baseline probes (1-4), two phases of treatment were implemented over 6 weeks. Respiratory lung volume-based training (RLVT) and subsequent performance was probed at sessions 5 to 7 and laryngeal-based training was added to the RLVT and probed at sessions 8 to 10. Visual biofeedback was used during RLVT to assist the motor learning process. Respiratory outcome measures of lung volume initiation, termination and excursion were objectively measured using respiratory plethysmography (InductoTrace), and cepstral and spectral-based acoustic measures were also determined at each time point. RESULTS: All participants showed improvement in one or more respiratory measures as well as reduced acoustic dysphonia severity following phase 1 of RLVT alone. Two participants achieved further marked improvement in acoustic voice measures after laryngeal-based training was added in phase 2 of treatment, but this was generally also accompanied by further improvement or stabilization of respiratory measures. CONCLUSION: Results from this preliminary study support the feasibility of RLVT for improving speech breathing behavior, and suggest that RLVT alone can improve objectively measured dysphonia severity.

Clinical Features of Essential Voice Tremor and Associations with Tremor Severity and Response to Octanoic Acid Treatment.

OBJECTIVES/HYPOTHESIS: The purpose of this study was to characterize the clinical features, tremor variability, and factors related to octanoic acid (OA) treatment response in essential voice tremor (EVT). STUDY DESIGN: Prospective, double blind, placebo-controlled, crossover study with secondary analysis. METHODS: Clinical tremor features in 16 individuals with EVT were comprehensively assessed, and correlations with acoustic tremor severity were determined. Intrasubject and intersubject variability measures were analyzed from 18 repeated measures for each acoustic tremor variable. Clinical correlates of treatment response were evaluated, and cumulative effects over a 2-week period of OA drug dosing were assessed. RESULTS: Participants with EVT were 90% female with a mean age of 70.31 (±8.68) years at the time of testing. Neurologist-rated body tremor beyond the vocal tract region was present in 69% of participants, and multiple vocal tract regions contributed to the voice tremor. The mean frequency of amplitude tremor was 4.67 Hz (±0.88). Respiratory tremor was evident in 50% of participants. Participants experienced moderate voice-related disability as assessed on the Voice Handicap Index-10 (19.38, ±8.50), and increased speaking effort. Acoustic tremor severity was significantly associated with severity of tremor affecting vocal tract structures. Overall intrasubject consistency was strong (single measures intraclass correlation coefficient = 0.701, P < .01), with high intersubject variability. Acoustic tremor severity was significantly, positively associated with treatment response, and results suggested a cumulative OA benefit for magnitude of amplitude tremor. CONCLUSIONS: This study identified common clinical correlates of EVT and demonstrated positive associations between acoustic tremor severity, severity of affected vocal tract structures, and response to treatment. LEVEL OF EVIDENCE: 2 Laryngoscope, 131:E2792-E2801, 2021.

A Systematic Review of the Physiological Effects of the Effortful Swallow Maneuver in Adults With Normal and Disordered Swallowing.

Purpose This systematic review summarizes the biomechanical and functional effects of the effortful swallow in adults with and without dysphagia, highlighting clinical implications and future research needs. Specifically, the effects of the effortful swallow on swallowing physiology, safety, and efficiency were identified, as well as the strengths and limitations of current research. Method Recommendations specified by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses were followed. A literature search of three databases and relevant articles cited in the searched studies was performed. Two evaluators independently analyzed the studies for eligibility criteria, and final inclusion of studies was decided by consensus. Evaluators also assessed each study for quality of evidence. Results Twenty-three studies were included in this systematic review. Main findings indicated that the effortful swallow generated greater pressures in the tongue-to-palate, pharynx, upper esophageal sphincter, and esophageal regions. Inconsistent results for hyolaryngeal excursion were reported, as well as for swallowing function. Instructions of the effortful swallow varied greatly across studies. Two of the 23 studies were judged to be of high quality, and the remaining studies were of medium quality based on the quality indicators of this review. Conclusions Biomechanical effects of the effortful swallow included increased pressures in the oral, pharyngeal, and esophageal regions. Future investigations should address the effects of the effortful swallow in individuals with dysphagia and its potential role as a rehabilitative maneuver. Moreover, standardization of the effortful swallow instructions based on its physiological and functional effects is essential.

Assessment of Tongue Position and Laryngeal Height in Two Professional Voice Populations.

Purpose To advance our current knowledge of singer physiology by using ultrasonography in combination with acoustic measures to compare physiological differences between musical theater (MT) and opera (OP) singers under controlled phonation conditions. Primary objectives addressed in this study were (a) to determine if differences in hyolaryngeal and vocal fold contact dynamics occur between two professional voice populations (MT and OP) during singing tasks and (b) to determine if differences occur between MT and OP singers in oral configuration and associated acoustic resonance during singing tasks. Method Twenty-one singers (10 MT and 11 OP) were included. All participants were currently enrolled in a music program. Experimental procedures consisted of sustained phonation on the vowels /i/ and /ɑ/ during both a low-pitch task and a high-pitch task. Measures of hyolaryngeal elevation, tongue height, and tongue advancement were assessed using ultrasonography. Vocal fold contact dynamics were measured using electroglottography. Simultaneous acoustic recordings were obtained during all ultrasonography procedures for analysis of the first two formant frequencies. Results Significant oral configuration differences, reflected by measures of tongue height and tongue advancement, were seen between groups. Measures of acoustic resonance also showed significant differences between groups during specific tasks. Both singer groups significantly raised their hyoid position when singing high-pitched vowels, but hyoid elevation was not statistically different between groups. Likewise, vocal fold contact dynamics did not significantly differentiate the two singer groups. Conclusions These findings suggest that, under controlled phonation conditions, MT singers alter their oral configuration and achieve differing resultant formants as compared with OP singers. Because singers are at a high risk of developing a voice disorder, understanding how these two groups of singers adjust their vocal tract configuration during their specific singing genre may help to identify risky vocal behavior and provide a basis for prevention of voice disorders.

The Low Mandible Maneuver: Preliminary Study of Its Effects on Aerodynamic and Acoustic Measures.

OBJECTIVES: The purpose of this preliminary study was to determine the aerodynamic and acoustic effects of the low mandible maneuver (LMM) as compared to normal voice production. METHODS: Ten participants with normal voice characteristics who were nonsingers produced sustained vowel and repeated syllable utterances during two different speaking conditions: using the LMM and using normal phonation posture. The LMM involves a wider vocal tract configuration with a lowered and relaxed jaw position. Acoustic recordings and analyses were performed to determine formants 1 and 2 (F1 and F2) and sound pressure level. Aerodynamic data were collected and analyzed to investigate the effects of the LMM on mean peak pressure, mean airflow, aerodynamic power, aerodynamic efficiency, and aerodynamic resistance. RESULTS: Participants showed greater aerodynamic efficiency, mean peak pressure, and sound pressure level during the LMM condition as compared to normal phonation. The LMM vocal tract configuration changes were also associated with a lowering of F1 and F2 relative to normal voice production. CONCLUSIONS: The lowering of the mandible and increased oral area that occurred during the LMM increased vocal efficiency and sound output without significant change to parameters that can be associated with increased vocal effort. These changes in filter configuration were associated with changes in vocal tract resonances. The LMM was readily learned and implemented by healthy participants in this study, and may have utility for singers in training as well as people with hyperfunctional voice disorders.

The Effect of Octanoic Acid on Essential Voice Tremor: A Double-Blind, Placebo-Controlled Study.

OBJECTIVES/HYPOTHESIS: The purpose of this study was to determine the effects of octanoic acid on acoustic, perceptual, and functional aspects of essential voice tremor (EVT). STUDY DESIGN: Prospective, double-blind, placebo-controlled, crossover study. METHODS: Sixteen participants with a diagnosis of EVT were randomized to a 3-week dosing condition of octanoic acid or placebo, followed by a 2-week washout period and crossover to the other condition for an additional 3 weeks. Baseline and post-testing sessions were completed before and at the completion of each condition. Primary outcome measures were the magnitude of amplitude and frequency tremor, measured from the acoustic signal. Secondary outcomes were auditory-perceptual ratings of tremor severity and self-ratings of voice handicap. RESULTS: Magnitude of amplitude and frequency tremor were significantly lower after 3 weeks of octanoic acid dosing as compared to the placebo condition. Auditory-perceptual ratings of tremor severity did not show significant differences between conditions. A trend toward better voice was seen for the sustained vowel ratings, but not the sentence-level ratings. No significant differences between conditions were seen on self-reported voice disability as assessed on the Voice Handicap Index-10. CONCLUSIONS: The results of this controlled investigation support the potential utility of octanoic acid for reducing the magnitude of tremor in people with EVT. Further research is needed to determine whether different dosing or treatment combinations can improve functional communication in EVT. LEVEL OF EVIDENCE: 1 Laryngoscope, 129:1882-1890, 2019.

The effect of anchors on reliability of endoscopic tremor ratings.

OBJECTIVES/HYPOTHESIS: The purpose of this study was to determine the effects of anchors and training on intrarater and inter-rater reliability for visual-perceptual, endoscopic tremor ratings. STUDY DESIGN: Prospective cohort study. METHODS: Nasoendoscopy recordings of 10 participants with a diagnosis of essential voice tremor were evaluated by five voice specialists using the Vocal Tremor Scoring System. Ratings were performed before, immediately after, and 4 weeks after implementation of a training program with anchor stimuli. Immediate and long-term post-training ratings were performed with simultaneous use of anchor samples for each rating. RESULTS: Intrarater reliability showed significant improvement from pretraining to immediate and long-term post-training. Mean correlation coefficients (Spearman's rho) increased from 0.71 at pretraining to 0.84 and 0.90 at immediate and long-term post-training, respectively. Inter-rater reliability was not affected by training with anchors, with mean correlation coefficients ranging from 0.62 at pretraining to 0.58 and 0.64 at immediate and long-term post-training, respectively. CONCLUSIONS: Consistent, reproducible ratings are critical for the interpretation and comparison of endoscopic tremor data. Reliability findings from this study indicate that the use of anchor samples as referents for making ordinal judgments about the severity of tremor in oropharyngeal and laryngeal regions was helpful for improving internal standards and consistency but less useful for calibrating across different raters. LEVEL OF EVIDENCE: 4 Laryngoscope, 2016 127:411-416, 2017.

The effect of speaking context on spectral- and cepstral-based acoustic features of normal voice.

The effect of speaking context on four cepstral- and spectral-based acoustic measures was investigated in 20 participants with normal voice. Speakers produced three different continuous speaking tasks that varied in duration and phonemic content. Cepstral and spectral measures that can be validly derived from continuous speech were computed across the three speaking contexts. Cepstral peak prominence (CPP), low/high spectral ratio, and the standard deviation (SD) of the low/high spectral ratio did not significantly differ across speaking contexts, and correlations for the first two measures were strong among the three speaking tasks. The SD of the CPP showed significant task differences, and relationships between the speaking contexts were generally moderate. These findings suggest that in speakers with normal voice, the differing phonemic content across several frequently used speaking stimuli minimally impacted group means for three clinically relevant cepstral- and spectral-based acoustic measures.

A Preliminary Quantitative Comparison of Vibratory Amplitude Using Rigid and Flexible Stroboscopic Assessment.

STUDY OBJECTIVE: The purpose of this study was to establish preliminary, quantitative data on amplitude of vibration during stroboscopic assessment in healthy speakers with normal voice characteristics. Amplitude of vocal fold vibration is a core physiological parameter used in diagnosing voice disorders, yet quantitative data are lacking to guide the determination of what constitutes normal vibratory amplitude. METHODS/STUDY DESIGN: Eleven participants were assessed during sustained vowel production using rigid and flexible endoscopy with stroboscopy. Still images were extracted from digital recordings of a sustained /i/ produced at a comfortable pitch and loudness, with F0 controlled so that levels were within ±15% of each participant's comfortable mean level as determined from connected speech. Glottal width (GW), true vocal fold (TVF) length, and TVF width were measured from still frames representing the maximum open phase of the vibratory cycle. To control for anatomic and magnification differences across participants, GW was normalized to TVF length. GW as a ratio of TVF width was also computed for comparison with prior studies. RESULTS: Mean values and standard deviations were computed for the normalized measures. Paired t tests showed no significant differences between rigid and flexible endoscopy methods. Interrater and intrarater reliability values for raw measurements were found to be high (0.89-0.99). CONCLUSIONS: These preliminary quantitative data may be helpful in determining normality or abnormality of vocal fold vibration. Results indicate that quantified amplitude of vibration is similar between endoscopic methods, a clinically relevant finding for individuals performing and interpreting stroboscopic assessments.

Aerodynamic and acoustic features of vocal effort.

OBJECTIVES: The purpose of this study was to determine the aerodynamic and acoustic features of speech produced at comfortable, maximal and minimal levels of vocal effort. STUDY DESIGN: Prospective, quasi-experimental research design. METHOD: Eighteen healthy participants with normal voice were included in this study. After task training, participants produced repeated syllable combinations at comfortable, maximal and minimal levels of vocal effort. A pneumotachometer and vented (Rothenberg) mask were used to record aerodynamic data, with simultaneous recording of the acoustic signal for subsequent analysis. Aerodynamic measures of subglottal pressure, translaryngeal airflow, maximum flow declination rate (MFDR), and laryngeal resistance were analyzed, along with acoustic measures of cepstral peak prominence (CPP) and its standard deviation (SD). RESULTS: Participants produced significantly greater subglottal pressure, translaryngeal airflow, and MFDR during maximal effort speech as compared with comfortable vocal effort. When producing speech at minimal vocal effort, participants lowered subglottal pressure, MFDR, and laryngeal resistance. Acoustic changes associated with changes in vocal effort included significantly higher CPP during maximal effort speech and significantly lower CPP SD during minimal effort speech, when each was compared with comfortable effort. CONCLUSIONS: For healthy speakers without voice disorders, subglottal pressure, translaryngeal airflow, and MFDR may be important factors that contribute to an increased sense of vocal effort. Changes in the cepstral signal also occur under conditions of increased or decreased vocal effort relative to comfortable effort.

Predictive value and discriminant capacity of cepstral- and spectral-based measures during continuous speech.

OBJECTIVES/HYPOTHESIS: The purpose of this study was to determine the relative strength of various cepstral- and spectral-based measures for predicting dysphonia severity and differentiating voice quality types. STUDY DESIGN: Prospective, quasi-experimental research design. METHODS: Twenty-eight dysphonic speakers and 14 normal speakers were included in this study. Among the dysphonic speakers, 14 had a predominant voice quality of breathiness and 14 had a predominant voice quality of roughness. Cepstral and spectral analyses of the first and second sentences of the Rainbow passage were performed, along with perceptual ratings of overall dysphonia severity. Linear regression was performed to determine the predictive capacity of each variable for dysphonia severity, and discriminant analysis determined the combination of variables that optimally differentiated the three voice quality types. RESULTS: A four-factor model that incorporated the cepstral- and spectral-based measures produced an R value of 0.899, explaining 81% of the variance in auditory-perceptual dysphonia severity. Cepstral peak prominence (CPP) showed the greatest predictive contribution to dysphonia severity in the regression model. The discriminant analysis produced two discriminant functions that included both CPP and its standard deviation (CPP SD) as significant contributors (P < 0.001), with an overall classification accuracy for the combined functions of 79%. CONCLUSIONS: Acoustic measures reflecting the distribution of harmonic energy and low- to high-frequency energy in continuous speech, along with the variability (standard deviations) of each, were highly predictive of dysphonia severity when combined in a multivariate linear model. Cepstral-based measures showed the highest capacity to discriminate voice quality types, with better classification accuracy for normal and dysphonic-breathy than for dysphonic-rough voices.

Spectral- and cepstral-based acoustic features of dysphonic, strained voice quality.

OBJECTIVES: We sought to determine whether spectral- and cepstral-based acoustic measures were effective in distinguishing dysphonic-strained voice quality from normal voice quality and whether these measures were related to auditory-perceptual ratings of strain severity. METHODS: Voice samples from 23 speakers with dysphonia characterized predominantly by strained voice quality and 23 speakers with normal voice were acoustically analyzed. Measures related to the prominence of the cepstral peak and the ratio of low- to high-frequency spectral energies, as well as the variation of each, were computed from continuous speech and a sustained vowel. Correlations to perceptually rated strain severity were determined. RESULTS: Measures related to the cepstrum were the strongest discriminators between dysphonic-strained voice and normal voice. Variation in the ratio of low- to high-frequency spectral energies also significantly differentiated the two speaker groups. All measures were significantly correlated with perceptually rated strain severity, including an acoustic severity index that incorporated both cepstral- and spectral-based measures. CONCLUSIONS: Cepstral- and spectral-based measures that have been previously studied in dysphonia characterized by breathiness and roughness are effective in distinguishing strained dysphonia from normal voice quality. The utility of these acoustic measures is supported by their moderate-to-high relationship with perceptually rated strain severity.

Functional connectivity and laterality of the motor and sensory components in the volitional swallowing network.

Functional neuroimaging has shown that multiple brain regions are active during volitional swallowing. Little is known, however, about which regions integrate motor execution and sensory feedback in the swallowing system. Although unilateral brain lesions in either hemisphere can produce swallowing deficits, some functional neuroimaging studies indicate that the left hemisphere has greater activation in certain sensory and motor-related swallowing regions. In this study, correlation coefficients were computed for five seed regions during volitional saliva swallowing to determine the functional relationships of these regions with the rest of the brain: the anterior and posterior insula, inferior frontal gyrus (BA44), primary sensory cortex (S1), and primary motor cortex (M1). A laterality index (LI) was derived that accounts for relative differences in total, positive connected voxels for the left/right hemisphere seeds. Clusters of significantly connected voxels were greater from the anterior and posterior insula than from the other three seed regions. Interactions of the insula with other brain regions were greater on the left than on the right during volitional swallowing. Group means showed laterality in the anterior insula (LI = 0.25) and the posterior insula (LI = 0.33). BA44 showed a lesser degree of difference in left versus right hemisphere interactions (LI = 0.12) while S1 did not show lateralization (LI = 0.02) and M1 showed some predominance of interactions in the right hemisphere (LI = -0.19). The greater connectivity from the left hemisphere insula to brain regions within and across hemispheres suggests that the insula is a primary integrative region for volitional swallowing in humans.

Position of the hyoid and larynx in people with muscle tension dysphonia.

OBJECTIVES/HYPOTHESIS: To determine whether radiographic measures of hyoid position, laryngeal position, and hyolaryngeal space during phonation were different for people with primary muscle tension dysphonia (MTD) as compared to control participants without voice disorders. STUDY DESIGN: Prospective, quasi-experimental research design. METHODS: Twenty participants, 10 with primary MTD and 10 without voice disorders who were age and sex matched were studied radiographically while producing phonation. Lateral x-ray images were obtained for each participant during three tasks: resting state, sustained phonation, and a swallow-hold maneuver. Vertical positions of the hyoid and larynx were measured on a Cartesian coordinate system and were normalized to reflect change from rest during phonation. RESULTS: Normalized, vertical hyoid, and laryngeal positions during phonation were significantly higher for people with MTD than for control participants. Normalized hyolaryngeal space during phonation did not show differences between groups. A low to moderate significant correlation for radiographically measured hyoid and laryngeal position and the total score from a subjective laryngeal palpatory scale were evidenced, but no relationship was evidenced for radiographic laryngeal position and the laryngeal position subscore of the palpatory examination. CONCLUSIONS: Objective determinants of physiology are critical for the differential diagnosis of MTD and its effective treatment. Radiographic findings from this study indicate that hyoid and laryngeal positions during phonation are higher in people with primary MTD as compared to people without voice disorders.