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Summary Objectives There is a necessity to include objective methods to the study protocol of voice. Such procedure will help not only in diagnosing and monitoring the course of treatment, but also in comparing the results of studies between research centers. Methods Vocal fold mucosal wave characteristics of 70 healthy people were made using videostrobokymographic open quotient (VSK OQ ) and electroglottographic quasi-open quotient (EGG QOQ ). Results Statistically significant differences were achieved regarding gender for the averaged values of VSK OQ as well as for values calculated from the posterior part of the vocal folds. A statistically significant correlation between the value of VSK OQ and age was observed for the posterior part of the glottis. Differences between gender and the value of EGG QOQ were observed. No statistically significant correlation between EGG QOQ and age was obtained. Conclusions VSK OQ and EGG QOQ are parameters characterizing glottal function in a coherent manner. These parameters can be included easily in phoniatric examination and help to objectify glottal function. [ABSTRACT FROM AUTHOR]

Summary Background Acoustic analysis of voice (AAV) and electroglottography (EGG) have been used for assessing vocal quality in patients with voice disorders. The effectiveness of these procedures for detecting mild disturbances in vocal quality in elite vocal performers has been controversial. Objective To compare acoustic parameters obtained by AAV and EGG before and after vocal training to determine the effectiveness of these procedures for detecting vocal improvements in elite vocal performers. Materials and Methods Thirty-three elite vocal performers were studied. The study group included 14 males and 19 females, ages 18–40 years, without a history of voice disorders. Acoustic parameters were obtained through AAV and EGG before and after vocal training using the Linklater method. Results Nonsignificant differences ( P  > 0.05) were found between values of fundamental frequency ( F 0 ), shimmer, and jitter obtained by both procedures before vocal training. Mean F 0 was similar after vocal training. Jitter percentage as measured by AAV showed nonsignificant differences ( P  > 0.05) before and after vocal training. Shimmer percentage as measured by AAV demonstrated a significant reduction ( P  < 0.05) after vocal training. As measured by EGG after vocal training, shimmer and jitter were significantly reduced ( P  < 0.05); open quotient was significantly increased ( P  < 0.05); and irregularity was significantly reduced ( P  < 0.05). Conclusions AAV and EGG were effective for detecting improvements in vocal function after vocal training in male and female elite vocal performers undergoing vocal training. EGG demonstrated better efficacy for detecting improvements and provided additional parameters as compared to AAV. [ABSTRACT FROM AUTHOR]

Summary Introduction Recent research has revealed that classically trained tenors tend to constrict epilaryngeal structures when singing in and above the passaggio (ie, the frequency region where register events typically occur). These constrictions complicate visibility of vocal fold oscillatory patterns with transoral rigid high-speed video endoscopy, thus limiting the current understanding of laryngeal dynamics in the passaggio region of tenors. Materials and Methods This investigation analyzed seven professionally trained western classical tenors using high-speed digital imaging (HSDI) at 20,000 frames per second via transnasal flexible endoscopy. The participants produced transitions (a) from modal to falsetto register and (b) from modal to stage voice above the passaggio (SVaP) during ascending pitch glides from A3 (220 Hz) to A4 (440 Hz) on vowel /i/. HSDI data were complemented by simultaneous acoustic and electroglottographic recordings. Results For many subjects both transition types were associated with constrictions of the epilaryngeal structures during the pitch glide. These constrictions appeared to be more distinct for the SVaP than for falsetto. No major irregularities of vocal fold oscillations in the sense of fundamental frequency jumps were observed for either transition type. However, during the transitions, the open quotient derived from the glottal area waveform (OQ GAW ) increased; in falsetto, the OQ GAW was greater and the electroglottographic cepstral peak prominence was lower than in SVaP. Conclusions Epilaryngeal constrictions should be considered typical for tenors singing at high fundamental frequencies. Vocal fold oscillatory patterns are changing not only for the register shift from modal to falsetto but also for the transition from modal to SVaP, indicating a need for laryngeal adjustments during these transitions. [ABSTRACT FROM AUTHOR]

Summary Several historical sources from the first half of the 19th century mention a distinct third register mechanism particular to tenor voices of that period. This so-called voce faringea— often described as an “intermediate” register—is a virtually forgotten historical singing practice used to extend the upper range of the voice, where the singer modifies falsetto, typically a weak and often feminine sound, into a more powerful, tenor-like vocal quality. Based on an evaluation of historical voice register theories, training strategies, and the sound ideals of the historical period, an informed discussion of that technique is developed. For this study, acoustic and electroglottographic signals for tones produced on the vowel /a/ by a professional tenor/countertenor in different vocal register mechanisms— voce faringea , falsetto, chest register, and mezza voce—were recorded using the VoceVista system. Analysis of the electroglottography (EGG) and audio data revealed specific characteristics of the voce faringea with regard to both the laryngeal mechanism and the sound spectrum, including high EGG contact quotient and low speed quotient values. EGG pulses were skewed significantly to the left and displayed a distinct knee shape during the de-contacting phase of the vocal folds, which consequently indicates a vibration with a clear mucosal wave. The long-term average spectrum and power spectrum exposed a considerable amplification and dislocation of F 2 in the direction of high frequencies, thus boosting the third harmonic and showing a strong concentration of acoustic energy in the area of the singer's formant cluster. [ABSTRACT FROM AUTHOR]

Background: Dysarthrophonia is often reported by hereditary spastic paraplegia (HSP) patients with SPG11 mutations but it has been poorly investigated., Objective: The goal of this study was to investigate dysarthrophonia in SPG11 patients using quantitative measures. The voice/speech of two patients and a non-affected mutation carrier was recorded and analyzed using electroglottography (EGG) and speech acoustics., Results: Dysarthrophonia showed a higher standard deviation of the average fundamental frequency, a three to eight times higher jitter, a 80-110 Hz higher mean fundamental frequency, and a two times higher fundamental frequency range. Diadochokinesis showed a pattern of a two to three times increase in the mean duration of the release burst of the phonemes /p/, /t/, /k/ as well as a 1.5 time increase in the mean vowel duration of the syllables /pa/, /ta/, /ka/., Conclusion: Non-invasive physiological methods (EGG and speech acoustics) offer essential tools for the assessment of dysarthrophonia in SPG11 patients.

Although the call repertoire and its communicative function are relatively well explored in Japanese macaques ( Macaca fuscata ), little empirical data are available on the physics and the physiology of this species' vocal production mechanism. Here, a 6 year old female Japanese macaque was trained to phonate under an operant conditioning paradigm. The resulting 'coo' calls and spontaneously uttered 'growl' and 'chirp' calls were recorded with sound pressure level (SPL) calibrated microphones and electroglottography (EGG), a non-invasive method for assessing the dynamics of phonation. A total of 448 calls were recorded, complemented by ex vivo recordings on an excised Japanese macaque larynx. In this novel multidimensional investigative paradigm, in vivo and ex vivo data were matched via comparable EGG waveforms. Subsequent analysis suggests that the vocal range (range of fundamental frequency and SPL) of the macaque was comparable to that of a 7-10 year old human, with the exception of low intensity chirps, the production of which may be facilitated by the species' vocal membranes. In coo calls, redundant control of fundamental frequency in relation to SPL was also comparable to that in humans. EGG data revealed that growls, coos and chirps were produced by distinct laryngeal vibratory mechanisms. EGG further suggested changes in the degree of vocal fold adduction in vivo , resulting in spectral variation within the emitted coo calls, ranging from 'breathy' (including aerodynamic noise components) to 'non-breathy'. This is again analogous to humans, corroborating the notion that phonation in humans and non-human primates is based on universal physical and physiological principles., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2018. Published by The Company of Biologists Ltd.)

Dysarthrophonia is a predominant symptom in many neurological diseases, affecting the quality of life of the patients. In this study, we produced a discriminant function equation that can differentiate MS patients from healthy controls, using electroglottographic variables not analyzed in a previous study. We applied stepwise linear discriminant function analysis in order to produce a function and score derived from electroglottographic variables extracted from a previous study. The derived discriminant function's statistical significance was determined via Wilk's λ test (and the associated p value). Finally, a 2 × 2 confusion matrix was used to determine the function's predictive accuracy, whereas the cross-validated predictive accuracy is estimated via the "leave-one-out" classification process. Discriminant function analysis (DFA) was used to create a linear function of continuous predictors. DFA produced the following model (Wilk's λ = 0.043, χ2 = 388.588, p < 0.0001, Tables 3 and 4): D (MS vs controls) = 0.728*DQx1 mean monologue + 0.325*CQx monologue + 0.298*DFx1 90% range monologue + 0.443*DQx1 90% range reading - 1.490*DQx1 90% range monologue. The derived discriminant score (S1) was used subsequently in order to form the coordinates of a ROC curve. Thus, a cutoff score of - 0.788 for S1 corresponded to a perfect classification (100% sensitivity and 100% specificity, p = 1.67e -22 ). Consistent with previous findings, electroglottographic evaluation represents an easy to implement and potentially important assessment in MS patients, achieving adequate classification accuracy. Further evaluation is needed to determine its use as a biomarker.

Objective: The aim of the present workis to correlate the perceptual parameters grade, roughness and breathiness of the GRB scale with the contact quotient (CQ) obtained by electroglotography., Material and Method: 70 samples of normal and pathological voices were analyzed by means of auditory-perceptual analysis and electroglotography. The perceptual analysis was carried out by two expert judges depending on the parameters grade, roughness and breathiness. The CQ values were obtained through the VoceVista System Version 3.3.7., Results: The results show a strong correlation between CQ and breathiness (r = -0.869), whereas between grade of dysphonia and CQ (r = -0.567), and roughness and CQ (r = 0.643) the correlation is average., Conclusions: It is possible to establish relationships between the vibrational behavior of the vocal folds and the resulting phenomenon that we perceive auditively. The most relevant parameter in this respect was breathiness. The correlation between grade, roughness and CQ was weaker., (Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.)

Summary Objectives The purpose of this study was to investigate electroglottography (EGG) contact quotient modulation with emotional state in the presence of increased arousal. Study Design A within-subject reversal paradigm using multiple experimental conditions. Methods A total of 11 healthy undergraduate students underwent emotion induction with intermittent startles to increase physiologic arousal. During emotion induction, they vocalized on the vowel /u/ while EGG was recorded. Results EGG contact quotient was significantly greater for negative emotions compared with positive emotions with increased arousal commensurate with past research. In addition, overall EGG contact quotient was greater with elevated arousal. However, the effect sizes were small. Conclusions EGG contact quotient appears to increase with elevated arousal and be greater for negative mood states than positive mood states confirming that emotion states directly influence vocal functioning. [ABSTRACT FROM AUTHOR]

Summary Objectives (1) To develop an automated algorithm to analyze electroglottographic (EGG) signal in continuous dysphonic speech, and (2) to identify EGG waveform parameters that correlate with the auditory-perceptual quality of strain in the speech of patients with adductor spasmodic dysphonia (ADSD). Study Design Software development with application in a prospective controlled study. Methods EGG was recorded from 12 normal speakers and 12 subjects with ADSD reading excerpts from the Rainbow Passage. Data were processed by a new algorithm developed with the specific goal of analyzing continuous dysphonic speech. The contact quotient, pulse width, a new parameter peak skew, and various contact closing slope quotient and contact opening slope quotient measures were extracted. EGG parameters were compared between normal and ADSD speech. Within the ADSD group, intra-subject comparison was also made between perceptually strained syllables and unstrained syllables. Results The opening slope quotient SO7525 distinguished strained syllables from unstrained syllables in continuous speech within individual subjects with ADSD. The standard deviations, but not the means, of contact quotient, EGGW50, peak skew, and SO7525 were different between normal and ADSD speakers. The strain-stress pattern in continuous speech can be visualized as color gradients based on the variation of EGG parameter values. Conclusions EGG parameters may provide a within-subject measure of vocal strain and serve as a marker for treatment response. The addition of EGG to multidimensional assessment may lead to improved characterization of the voice disturbance in ADSD. [ABSTRACT FROM AUTHOR]

Summary Vocal-fold vibration can be analyzed in a noninvasive way by registering impedance changes within the glottis, through electroglottography. The morphology of the electroglottographic (EGG) signal is related to different vibratory patterns. In the literature, a characteristic knee in the descending portion of the signal has been reported. Some EGG signals do not exhibit this particular knee and have other types of events (inflection events) throughout the ascending and/or descending portion of the vibratory cycle. The goal of this work is to propose an automatic method to identify and classify these events. A computational algorithm was developed based on the mathematical properties of the EGG signal, which detects and reports events throughout the contact phase. Retrospective analysis of EGG signals obtained during routine voice evaluation of adult individuals with a variety of voice disorders was performed using the algorithm as well as human raters. Two judges, both experts in clinical voice analysis, and three general speech pathologists performed manual and visual evaluation of the sample set. The results obtained by the automatic method were compared with those of the human raters. Statistical analysis revealed a significant level of agreement. This automatic tool could allow professionals in the clinical setting to obtain an automatic quantitative and qualitative report of such events present in a voice sample, without having to manually analyze the whole EGG signal. In addition, it might provide the speech pathologist with more information that would complement the standard voice evaluation. It could also be a valuable tool in voice research. [ABSTRACT FROM AUTHOR]

Introduction: The objective was to study the behavior of the larynx during shouted voice production, when the larynx is exposed to extremely high subglottic pressure., Materials and Methods: The study involved electroglottographic, acoustic, and aerodynamic analyses of shouts produced at maximum effort by three male participants., Results and Discussion: Under a normal speaking voice, the voice sound pressure level (SPL) is proportional to the subglottic pressure. However, when the subglottic pressure reached high levels, the voice SPL reached a maximum value and then decreased as subglottic pressure increased further. Furthermore, the electroglottographic signal sometimes lost its periodicity during the shout, suggesting irregular vocal fold vibration.

The hypotheses of the present study were that the maximum frequency of fluctuation of electroglottographic (EGG) signals in the expiration phase of volitional cough (VC) reflects the cough efficiency and that this EGG parameter is affected by impaired laryngeal closure, expiratory effort strength, and gender. For 20 normal healthy adults and 20 patients diagnosed with unilateral vocal fold paralysis (UVFP), each participant was fitted with EGG electrodes on the neck, had a transnasal laryngo-fiberscope inserted, and was asked to perform weak/strong VC tasks while EGG signals and a high-speed digital image of the larynx were recorded. The maximum frequency was calculated in the EGG fluctuation region coinciding with vigorous vocal fold vibration in the laryngeal HSDIs. In addition, each participant underwent spirometry for measurement of three aerodynamic parameters, including peak expiratory air flow (PEAF), during weak/strong VC tasks. Significant differences were found for both maximum EGG frequency and PEAF between the healthy and UVFP groups and between the weak and strong VC tasks. Among the three cough aerodynamic parameters, PEAF showed the highest positive correlation with the maximum EGG frequency. The correlation coefficients between the maximum EGG frequency and PEAF recorded simultaneously were 0.574 for the whole group, and 0.782/0.717/0.823/0.688 for the male/female/male-healthy/male-UVFP subgroups, respectively. Consequently, the maximum EGG frequency measured in the expiration phase of VC was shown to reflect the velocity of expiratory airflow to some extent and was suggested to be affected by vocal fold physical properties, glottal closure condition, and the expiratory function.

Although it has been shown in previous research (Orlikoff, 1991; Henrich et al, 2005; Kuang et al, 2014; Awan, 2015) that there exists a relationship between the electroglottogram (EGG) waveform and the acoustic signal, this relationship is still not fully understood. To investigate this relationship, the EGG and acoustic signals were measured for four male amateur choir singers who each produced eight consecutive tones of increasing and decreasing vocal intensity. The EGG signals were processed cycle-synchronously to obtain the discrete Fourier transform, and the data were used as an input to a clustering algorithm. The acoustic signal was analyzed in terms of sound pressure level (dB SPL) and fundamental frequency (f o ) of vibration, and the results of both EGG and acoustic analysis were depicted on a two-dimensional plane with f o on the x-axis and SPL on the y-axis. All the subjects were seen to have a weak, near-sinusoidal EGG waveform in their lowest SPL range, whereas increase in SPL coincided with progressive enrichment in harmonic content of the EGG waveforms. The results of the clustering were additionally used to classify waveforms across subjects to enable inter-subject comparisons and assessment of individual strategies of exploring the f o -SPL dimensions. In these male subjects, the EGG waveform shape appeared to vary with SPL and to remain essentially constant with f o over one octave., (Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

The electroglottographic (EGG) contact quotient (CQegg), an estimate of the relative duration of vocal fold contact per vibratory cycle, is the most commonly used quantitative analysis parameter in EGG. The purpose of this study is to quantify the CQegg's relation to the closed quotient, a measure more directly related to glottal width changes during vocal fold vibration and the respective sound generation events. Thirteen singers (six females) phonated in four extreme phonation types while independently varying the degree of breathiness and vocal register. EGG recordings were complemented by simultaneous videokymographic (VKG) endoscopy, which allows for calculation of the VKG closed quotient (CQvkg). The CQegg was computed with five different algorithms, all used in previous research. All CQegg algorithms produced CQegg values that clearly differed from the respective CQvkg, with standard deviations around 20% of cycle duration. The difference between CQvkg and CQegg was generally greater for phonations with lower CQvkg. The largest differences were found for low-quality EGG signals with a signal-to-noise ratio below 10 dB, typically stemming from phonations with incomplete glottal closure. Disregarding those low-quality signals, we found the best match between CQegg and CQvkg for a CQegg algorithm operating on the first derivative of the EGG signal. These results show that the terms "closed quotient" and "contact quotient" should not be used interchangeably. They relate to different physiological phenomena. Phonations with incomplete glottal closure having an EGG signal-to-noise ratio below 10 dB are not suited for CQegg analysis., (Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

This paper examines age-related differences in voice quality between 15 young and 15 old speakers, using electroglottographic (EGG) recordings of three elicitation types: sustained vowels, hVd word lists, and readings of the Rainbow Passage. For each elicitation type, fundamental frequency (F0), contact quotient (Qx), and their standard deviations are analysed. Results found, for all three elicitations, that Qx was significantly lower for older speakers. F0 was higher for the older speakers, but this was only significant for the hVd word lists. Sustained vowels were used to examine the effect of target pitch and loudness on F0 and Qx. Both Qx and F0 were raised with increased target loudness. The hVd word lists were used to examine the phonetic effects of different vowels. Lip rounded vowels had higher Qx than non-lip rounded vowels. Readings of the Rainbow Passage encompassed prosodic and phonetic variations in F0 and Qx, in addition to voice quality. F0 and Qx contours of the hVd word lists and the vowel/ei/taken from the Rainbow Passage were analysed using the discrete cosine transform. The hVd frame produced coarticulation effects on the Qx contour, but no such effects were evident for the vowel /ei/. The study concluded that using multiple elicitation types is beneficial in the study of the effect of age on the voice, and that analysing contour tracks for F0 and Qx will allow further examination of how prosodic and phonetic effects interact with age-related changes in voice quality.

Speech and voice symptomatology (dysarthrophonia) are often reported by patients with myasthenia gravis (MG). However, they have been poorly investigated despite their significant impact on quality of life. Quantitative methods for the assessment of dysarthrοphonia could facilitate the evaluation of these common MG symptoms. The goal of this study was to investigate the phonatory (sustained phonation and reading) and speech (diadochokinesis) function in MG patients using quantitative measures. The voice/speech of 12 MG patients (7 with anti-AchR and 5 with anti-MuSK antibodies) and 24 age-matched healthy controls was recorded and analyzed using electroglottography (EGG) and speech acoustics. For the analysis of voice, the variables that were found to distinguish MG patients compared to healthy controls were a higher average fundamental frequency (P<0.05), a higher standard deviation of the average fundamental frequency (P<0.001), a higher mean fundamental frequency of the vibrating vocal folds (P<0.005) and a higher fundamental frequency range (P<0.005). The analysis of diadochokinesis showed that MG patients had a higher mean duration of the silent interval between a series of repetitive /pa/ syllables (P<0.05), of the sound /t/ (P=0.05) and of the silent interval between a series of repetitive /ka/syllables (P<0.05). No statistical differences were found in any of these variables between the MG subgroups with anti-AchR or anti-MuSK antibodies. This study demonstrates that non-invasive physiological methods (EGG and speech acoustics) offer essential tools for the assessment of dysarthrophonia in MG patients., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objectives: The study aimed to investigate whether humming can immediately improve the regularity of vocal fold vibration on electroglottography (EGG) and laryngeal high-speed digital imaging (HSDI) in patients with organic dysphonia (OD)., Methods: In a series of 49 dysphonic patients who were diagnosed to have benign mass lesions in the vocal folds and an equal number of non-dysphonic speakers, perturbation parameters were calculated on the acoustic (Ac) and EGG signals during natural and humming phonation. In addition, 11 OD patients and as many non-dysphonic speakers underwent simultaneous EGG and HSDI video recording under laryngofiberscopy while performing the two tasks. The perturbation parameters of the EGG signals as well as the glottal area waveforms (GAW), which were extracted from the HSDI movies, were calculated, and the correlations between both perturbation parameters were analyzed., Results: Humming achieved significant improvements in the EGG perturbation parameters in both groups. More than half of the OD patients showed decreased EGG perturbation parameters to the level of those during natural phonation in the control group. With respect to the GAW analysis, moderate correlations were observed between both period and amplitude perturbation parameters (period: r = 0.63, amplitude: r = 0.41). Humming decreased both GAW perturbation parameters significantly in the OD and control subjects combined., Conclusions: These results demonstrate that in OD patients, humming has a potential to improve voice quality by stabilizing the vocal fold oscillation, and suggest that humming can remove the functional component in the vocal disturbance instead of the mechanical effect of the mass lesions., (Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose: To combine vocal tract measurements with dynamic MRI of the lungs to provide fundamental insights into the lung physiology during singing., Methods: To analyze vocal fold oscillatory patterns during dynamic lung MRI, an electroglottography (EGG) system was modified to allow for simultaneous EGG measurements during MR image acquisitions. A low-pass filter was introduced to suppress residual radiofrequency (RF) coupling into the EGG signal. RF heating was tested in a gel phantom to ensure MR safety, and functionality of the EGG device was assessed in a volunteer experiment at singing frequencies from A5 to A3. In the recorded EGG signals, remaining RF interferences were removed by independent component analysis post processing, and standard EGG parameters such as fundamental frequency, contact quotient and jitter were calculated. In a second volunteer experiment, EGG recordings were compared with lung diameter measurements from 2D time-resolved trueFISP acquisitions., Results: RF heating measurements resulted in less than 1.2°C temperature increase in the gel phantom. EGG parameters measured during MR imaging are within the range of ideal values. In the lung measurement, both the lung diameter and the EGG recordings could be successfully performed with only minimal interference., Conclusion: EGG recording is pos sible during dynamic lung MRI, and glottal activity can be studied safely at 1.5T. Magn Reson Med 76:1629-1635, 2016. © 2015 International Society for Magnetic Resonance in Medicine., (© 2015 International Society for Magnetic Resonance in Medicine.)

Background: Pompe disease is a progressive metabolic myopathy. Disease progression is characterized, among other features, by progressive dysfunction of the voice apparatus. The aim of this study was to employ electroglottographic, acoustic and nasalance measurement methods on patients with late-onset Pompe disease in order to provide detailed information on the effect of the disease on voice quality. Voice quality is the key factor for estimating the effectiveness of ERT in late-onset Pompe disease. The study compared clinical phoniatric examination with electroglottographic, acoustic and nasalance measurement methods. The consistency of the aforementioned analyses was assessed., Methods: The study examined 19 patients with late-onset Pompe disease (including 9 with the juvenile form of the disease). Of these, a total of 17 patients underwent otolaryngological examination with detailed phoniatric evaluation of their articulatory organs. Electroglottographic recordings and nasalance measurements (using the nasalance Separator Handle) were obtained from all patients. MATLAB (COVAREP toolkit) was used to analyse voice recording data., Results: Dysphonia observed in patients with late-onset Pompe disease is mainly caused by dysfunction of vocal fold closure and weakness of vocal muscle. However, substantial speech nasality is caused by insufficient closure of the soft palate. Electroglottographic signal analysis, acoustic and nasalance testing methods indicated that more significant changes in the function of the voice apparatus presented in the juvenile form than in the adult form of late-onset Pompe disease., Conclusions: It was found that speech nasality and electroglottographic tests are more repeatable, comparable and versatile than phoniatric examination, allowing for earlier detection of voice pathology in late-onset Pompe disease. These sensitive and non-invasive acoustic and electroglottographic methods allow for the tracking of changes in voice as patients undergo treatment or as the disease progresses.

The vocal folds play a key role in the process of phonation. Cyclical movements of the vocal folds model a space called glottis, what leads to voice formation. The space contains surface between the vocal folds and the inner surface of the arytenoid cartilages. The best indicator of the vocal folds vibratory function is the mucosal wave. The presence and size of the mucosal wave is widely recognized as an indicator of tension and plasticity of vocal folds. It is also essential in the process of creating a proper, resonant voice. In the article, current knowledge of mucosal wave imaging techniques is given. Imaging can be carried out directly and indirectly. Among the direct methods, the following are distinguished: laryngostroboscopy, laryngovideostroboscopy, videokymography and high-speed digital imaging. Indirect methods include: electroglottography, photoglottography and ultrasonography., (© 2016 MEDPRESS.)

Summary: Objectives: The aim of this study was to verify whether the electroglottography (EGG) perturbation parameters could be superior indicators to traditional acoustic (Ac) measures, particularly for the detection of mild vocal roughness. Methods: Thirty-nine participants with muscle tension dysphonia (the MTD group), 48 dysphonic participants with vocal fold lesions (the organic group), and 40 nondysphonic participants (the control group) were enrolled in the study. Based on the severity of vocal roughness, each of the two dysphonic groups was divided into mildly and severely dysphonic subgroups. The Ac and EGG signals during sustained /e:/ phonation were recorded simultaneously. The period and amplitude perturbation quotients of both signals (Ac-PPQ/-APQ and EGG-PPQ/-APQ) were calculated. The receiver operating characteristic (ROC) analyses were applied to evaluate the discriminative capabilities. Results: In the analyses between the control and each of the two dysphonic groups, the values of the areas under the curve (AUC) for EGG-PPQ were significantly higher than those for Ac-PPQ. Next, the ROC analyses between the control and mildly dysphonic MTD subgroup demonstrated that the AUC values for EGG-PPQ/EGG-APQ were significantly higher than those for Ac-PPQ/Ac-APQ. In the analyses of the mildly dysphonic organic group, the AUC value for EGG-PPQ was significantly higher than that for Ac-PPQ. Conclusions: The present study demonstrated that both the period and the amplitude perturbation parameters of the EGG signals showed higher diagnostic accuracies than those of Ac signals, especially for the detection of mild vocal roughness. These results suggest that the EGG perturbation parameters could provide better information than the traditional Ac perturbations. [Copyright &y& Elsevier]

Objective. The present study aimed to investigate the vocal tract and glottal function during and after phonation into a tube and a stirring straw. Methods. A male classically trained singer was assessed. Computerized tomography (CT) was performed when the subject produced [a:] at comfortable speaking pitch, phonated into the resonance tube and when repeating [a:] after the exercise. Similar procedure was performed with a narrow straw after 15 minutes silence. Anatomic distances and area measures were obtained from CT midsagittal and transversal images. Acoustic, perceptual, electroglottographic (EGG), and subglottic pressure measures were also obtained. Results. During and after phonation into the tube or straw, the velum closed the nasal passage better, the larynx position lowered, and hypopharynx area widened. Moreover, the ratio between the inlet of the lower pharynx and the outlet of the epilaryngeal tube became larger during and after tube/straw phonation. Acoustic results revealed a stronger spectral prominence in the singer/speaker's formant cluster region after exercising. Listening test demonstrated better voice quality after straw/tube than before. Contact quotient derived from EGG decreased during both tube and straw and remained lower after exercising. Subglottic pressure increased during straw and remained somewhat higher after it. Conclusion. CT and acoustic results indicated that vocal exercises with increased vocal tract impedance lead to increased vocal efficiency and economy. One of the major changes was the more prominent singer's/speaker's formant cluster. Vocal tract and glottal modifications were more prominent during and after straw exercising compared with tube phonation. [ABSTRACT FROM AUTHOR]

Objectives: The purpose was to assess whether cervical muscular contraction during phonation influences the period and amplitude perturbation quotients (PPQ and APQ, respectively) of electroglottographic (EGG) signals, and whether high-pass filtering can attenuate these effects., Study Design: Prospective., Methods: We included 19 nondysphonic speakers and 21 patients with muscle tension dysphonia. During the recording of acoustic and EGG signals, each participant was instructed to naturally phonate sustained vowels /i:/ and /a:/ (NP tasks), and additionally, each nondysphonic participant was asked to phonate the same vowels in a nondysphonic voice quality while contracting the cervical muscles (muscular contracted phonation [MCP] tasks). To confirm the contraction, surface and needle electromyography (EMG) was performed. The EGG signals were high-pass filtered at different cutoff frequencies from 0 to 90 Hz and were subsequently analyzed for the PPQ and APQ., Results: Compared with the NP tasks, the MCP tasks enhanced the cervical EMG activities ranging from 0 to more than 1000 Hz, but conferred only low-frequency noise to the EGG signals under 50 Hz and increased the values for EGG-APQ, but not EGG-PPQ. These EGG-APQ values exhibited gradual decreases after high-pass filtering with an increase in the cutoff frequency ranging from 0 to 50 Hz in both groups, followed by plateaus during the MCP tasks in the nondysphonic group., Conclusions: The present results demonstrate that cervical muscular contraction seriously affects the EGG-APQ values for unfiltered EGG signals independent of the EMG activities and that appropriate high-pass filtering over 50 Hz can attenuate these effects., (Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Phonation into glass tubes ('resonance tubes'), keeping the free end of the tube in water, has been a frequently used voice therapy method in Finland and more recently also in other countries. The purpose of this exploratory study was to investigate what effects tube phonation with and without water has on the larynx. Two participants were included in the study. The methods used were high-speed imaging, electroglottographic observations of vocal fold vibrations, and measurements of oral pressure during tube phonation. Results showed that the fluctuation in the back pressure during tube phonation in water altered the vocal fold vibrations. In the high-speed imaging, effects were found in the open quotient and amplitude variation of the glottal opening. The open quotient increased with increasing water depth (from 2 cm to 6 cm). A modulation effect by the water bubbles on the vocal fold vibrations was seen both in the high-speed glottal area tracings and in the electroglottography signal. A second experiment revealed that the increased average oral pressure was largely determined by the water depth. The increased open quotient can possibly be explained by an increased abduction of the vocal folds and/or a reduced transglottal pressure. The back pressure of the bubbles also modulates glottal vibrations with a possible 'massage' effect on the vocal folds. This effect and the well-defined average pressure increase due to the known water depth are different from those of other methods using a semi-occluded vocal tract.

Objectives: To date, only a few studies have examined the possible relationship between electroglottographic (EGG) data and spectral characteristics of the voice. This study examined the possible association between EGG signal data (contact quotient [CQ] and decontacting phase profile) and spectral moments of the acoustic signal (spectral mean, spectral standard deviation (SD), spectral skewness, and spectral kurtosis). Furthermore, the possible effects of gender on these measurements were analyzed., Methods: Sustained vowel /ɑ/ productions were obtained from 48 normophonic individuals (24 adult males and 24 adult females). The central 1-second portions of the acoustic vowel samples were analyzed for spectral moments, and the EGG signal was analyzed for CQ (CQEGG), fundamental frequency (F0), and decontacting phase profile., Results: Across all subjects, the spectral characteristics of the voice (in particular, spectral SD, skewness, and kurtosis) are significantly related to changes in the relative duration of vocal fold contact (as measured via CQEGG). In addition, significant effects of the profile of the EGG decontacting phase (ie, concave down/"knee" vs concave up/"no knee") on spectral SD were also observed, as well as a strong trend for decontacting phase profile to influence the spectral mean., Discussion: Although the degree of vocal fold contact and differences in decontacting phase profile may have an influence on the spectral characteristics of the acoustic voice signal, the strength of correlations between CQEGG values and measures of spectral moments only accounted for approximately 13-16% of the variation in spectral distribution characteristics. These results stress the importance of the transformative role of the supraglottal vocal tract in producing an acoustic output that maintains some of the characteristics of the glottal source, but which modifies the source characteristics in ways not completely accounted for by single parameters such as CQEGG or EGG profile., (Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Objective: To make a comparative analysis on the closed quotient (CQ) of the sustained vowel /e/ while fasting and nonfasting., Study Design: Cross-sectional study., Methods: A total of 20 male subjects were enrolled. The mean age was 30.45 ± 8.79 years with a range of 20-48 years. The mean weight while nonfasting was 79.66 ± 12.91 kg and while fasting was 78.51 ± 12.70 kg. Demographic data included age, history of smoking, and weight. All subjects were evaluated while fasting and nonfasting. All subjects underwent laryngeal electroglottography while phonating the vowel /e/ at a comfortable pitch and loudness. The mean CQ, range, and standard deviations were computed while fasting and nonfasting. The degree of phonatory effort and vocal fatigue was also reported on a scale of 0-3., Results: The difference in weight while fasting and nonfasting was statistically significant (P=0.001). There was no significant difference between the mean CQ while fasting versus nonfasting (44.49 ± 1.15 and 44.30 ± 1.41, P=0.94). The difference in the mean grade of phonatory effort was borderline significant (P=0.059) with 40% of the subjects having an increase in effort. With respect to vocal fatigue, there was an increase in the average while fasting by 0.25, which was statistically nonsignificant (P=0.109)., Conclusions: The mean CQ during sustained /e/ is not affected by fasting. The presence of increased vocal effort and vocal fatigue could be secondary either to dehydration or respiratory muscle fatigue accompanying the weight loss., (Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Objective: The purpose of this study was to describe changes in aerodynamic and electroglottographic (EGG) measures immediately after completing three semi-occluded vocal tract (SOVT) exercises., Study Design: Prospective case series., Methods: Aerodynamic and EGG measurements were obtained before and immediately after performing three SOVTs (straw phonation, lip trill, and tongue trill) in four singers for prepost comparisons to evaluate laryngeal changes persisting beyond the execution of SOVTs., Results: Mean air flow, sound pressure level, and EGG closed quotient tended to increase after completing SOVTs. The magnitude of change and consistency of change in measures across the SOVTs varied from subject-to-subject., Conclusions: Aerodynamic and EGG changes did occur during and immediately after completing SOVTs. However, there was marked variability within and across participants. Further investigation is needed to better understand which SOVTs are likely to benefit a particular individual., (Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)