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Previous research has suggested that the peaks in the first derivative (dEGG) of the electroglottographic (EGG) signal are good approximate indicators of the events of glottal opening and closing. These findings were based on high-speed video (HSV) recordings with frame rates 10 times lower than the sampling frequencies of the corresponding EGG data. The present study attempts to corroborate these previous findings, utilizing super-HSV recordings. The HSV and EGG recordings (sampled at 27 and 44 kHz, respectively) of an excised canine larynx phonation were synchronized by an external TTL signal to within 0.037 ms. Data were analyzed by means of glottovibrograms, digital kymograms, the glottal area waveform and the vocal fold contact length (VFCL), a new parameter representing the time-varying degree of 'zippering' closure along the anterior-posterior (A-P) glottal axis. The temporal offsets between glottal events (depicted in the HSV recordings) and dEGG peaks in the opening and closing phase of glottal vibration ranged from 0.02 to 0.61 ms, amounting to 0.24-10.88% of the respective glottal cycle durations. All dEGG double peaks coincided with vibratory A-P phase differences. In two out of the three analyzed video sequences, peaks in the first derivative of the VFCL coincided with dEGG peaks, again co-occurring with A-P phase differences. The findings suggest that dEGG peaks do not always coincide with the events of glottal closure and initial opening. Vocal fold contacting and de-contacting do not occur at infinitesimally small instants of time, but extend over a certain interval, particularly under the influence of A-P phase differences. [ABSTRACT FROM AUTHOR]

Objective: This study analyzes the effects of the vocal exercises called semi-occluded nasal tract exercises (SONTEs), which were carried out with a new appliance that extends the nasal cavity as a part of the vocal tract. The acoustic, aerodynamic and electroglottographic (EGG) measurements were compared with those of the traditional semi-occluded vocal tract exercises (SOVTEs) of phonation in water., Methods: In this study, 34 women were randomly asked to perform phonation in water for 5 min through the nasal and oral routes with the sounds /m/ and /ɔ/, respectively, using a tube with a submersion depth of 5 cm. The acoustic, aerodynamic and EGG measurements before and after the exercises were analyzed using the appropriate statistical methods., Results: No significant difference was found in the time and frequency domain parameters before and after the exercises, except for the amplitude perturbation quotient (APQ) values, which decreased after both exercises. In addition, there was no significant difference in any aerodynamic parameters before and after the exercises, but the mean SPL values significantly increased after both exercises. The oral and nasal peak inspiratory flow rates increased after both exercises, but the increase peaked after the SONTEs implementation. As expected, the EGG-jitter and EGG-periodicity values had a reciprocal interaction with each other, while differences were observed between the values of the vocal fold movements measured in both exercises., Conclusions: SONTEs may be as effective as the conventional SOVTEs because it made tube phonation into water possible through artificial extension of the nasal cavity and increased the resonant effect by using the positive effects based on the principles of SOVTEs., Competing Interests: CONFLICT OF INTEREST Authors declare that there is no conflict of interest in this study., (Copyright © 2022 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

The deleterious effects of smoking on laryngeal mucosa are indisputable. Smoking not only causes histologic (microscopic) alterations in the vocal fold epithelium but also affect the acoustic property of voice. The goal of this study was to determine the effects of smoking on the laryngeal structures and phonatory physiology via videostroboscopy, acoustic voice analysis and electroglottography. Cross-sectional and observational study was carried out in Department of ENT, Pt. J. N. M. Medical College, Raipur, in 100 male volunteers (50 smokers and 50 nonsmokers) between the ages of 18 and 60 years with no voice complaints. All subjects were analyzed for detailed history and underwent videostroboscopic, acoustic voice analysis and electroglottographic examination. Videostroboscopic examination results showed significant relationships between smoking and abnormal vocal fold edge, abnormal texture, edema, erythema, abnormal mucosal cover, abnormal phase symmetry and abnormal pliability/stiffness. Voice analysis showed that smoking has a clear effect on some acoustic voice and electroglottographic parameters. The parameters most commonly affected by smoking are fundamental frequency (F0), jitter, shimmer, F0 tremor, normalized noise energy, signal noise ratio, maximum phonation time (MPT), s/z ratio, opening rate and closing rate. The results indicate that smoking has a significant effect on laryngeal structures and phonatory physiology. [ABSTRACT FROM AUTHOR]

Highlights: [•] Electroglottogram and microphone signals analysis in normal and dysphonic subjects. [•] SampEn and cross-SampEn indicators. [•] SampEn and cross-SampEn statistically higher in pathological subjects. [•] Microphone signal more complex than electroglottogram. [ABSTRACT FROM AUTHOR]

Summary: The phonation threshold pressure (PTP) is defined as the lowest subglottal pressure needed for obtaining and sustaining vocal fold oscillation. It has been found to increase during vocal fatigue. In the present study, PTP is measured together with the threshold pressure needed for vocal fold collision; henceforth, the collision threshold pressure (CTP). PTP and CTP are compared before and after loud, prolonged vocalization in singer and nonsinger voices. Ten subjects repeated the vowel sequence /a, e, i, o, u/ at a Sound Pressure Level of at least 80dB at 0.3m for 20 minutes. Audio and electroglottography signals were recorded before and after this exercise. At the same time, oral pressure was registered while the subjects produced a diminuendo repeating the syllable /pa:/, thus acquiring an approximate of the subglottal pressure. CTP and PTP increased significantly after the vocal loading in the nonsinger subjects. On the other hand, singers reported no substantial effect of the exercise, and most singers had a mean after-to-before ratio close to 1 for both CTP and PTP. [Copyright &y& Elsevier]

Objective. To compare the mean and standard deviation (SD) of the contact quotient (CQ) of the sustained vowels ([a] and [e]) in multiple sclerosis (MS) patients versus controls. Study Design. Cross-sectional study. Materials and Methods. Thirty-nine subjects (24 patients and 15 controls) participated in this study. Laryngeal electroglottography was performed on all subjects while phonating the vowels [a] and [e] at a comfortable pitch and loudness. The fundamental frequency, mean CQ, SDs, and jitter were computed for both vocal tasks. Results. The mean age of the MS group was 36.25 + 10.61 years. All laryngeal examinations were normal and five patients with MS had dysphonia described as voice breaks and fatigue in connected speech. For both vowels [a] and [e], the mean closed quotients were comparable in groups, MS and control (43.90 vs 53 for [a] and 44.75 vs 43.63 for [e]) with no significant difference. When comparing five MS patients with dysphonia versus controls, for the vowel [a], the mean closed quotient was significantly lower in MS patients with dysphonia (P values of 0.043). Conclusion. The mean closed quotient for sustained vowels [a] and [e] are comparable in MS patients and healthy controls except in patients with dysphonia. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis. The purpose of this study was to reevaluate the possible effect of gender on measures of electroglottographic contact quotient (CQ). In addition to criterion threshold methods frequently used for the computation of CQ's via electroglottography (EGG), derivative based methods of computing the EGG CQ that have not been previously evaluated in regard to their effectiveness in discriminating between male versus female EGG waveforms were also examined. Study Design. Causal, mixed design. Methods. EGG waveforms were recorded during sustained vowel production from normal voice men and women (total N = 50). Measures of EGG CQ were calculated using eight criterion thresholds (25-60% in 5% increments). In addition, CQs were computed using the EGG derivative (DEGG) as well as via two hybrid methods that combine thresholds with measures from the DEGG. Results. Only CQs calculated via the DEGG showed a statistically significant difference in the direction anticipated via previous research (ie, men > women). In addition, the DEGG was the only method to show statistically significant differences in CQ useful in discriminating between "knee"-shaped opening phases observed in 76% of the men versus no "knee" opening phases observed in 64% of the women. Conclusions. The DEGG may provide advantages over other methods of EGG CQ analysis that are useful in revealing possible gender differences in vocal physiology. Further studies that examine the relationship between EGG, DEGG, and visualization of vocal fold dynamics via high-speed video may provide further insight into the possible differences between adult male versus female contacting and decontacting points during comfortable pitch and loudness phonation. [ABSTRACT FROM AUTHOR]

Contact quotient (CQ), measured by electroglottogram (EGG), is a ratio which illustrates the duration of vocal fold contact during one vocal fold period. In the present study CQEGG was calculated from a sustained vowel phonation in three different phonation types (breathy, normal, pressed) at three amplitude threshold levels (25%, 35%, 50%). CQEGG values were compared with experts' perceptual evaluation of the firmness of phonation. The contact time of the vocal folds differed significantly between the different phonation types at all threshold levels ( P < 0.01). Perceptual evaluation correlated best with CQEGG at threshold levels 25% and 35%. The results of the linear regression model suggested that by using threshold level 25% the effect of F0 and SPL on CQEGG were not significant. [ABSTRACT FROM AUTHOR]

Abstract: The use of high-speed videoendoscopy (HSV) for the assessment of vocal-fold vibrations dictates the development of efficient techniques for glottal image segmentation. We present a new glottal segmentation method using a local-based active contour framework. The use of local-based features and the exploitation of the vibratory pattern allows for dealing effectively with image noise and cases where the glottal area consists of multiple regions. A scheme for precise glottis localization is introduced, which facilitates the segmentation procedure. The method has been tested on a database of 60 HSV recordings. Comparisons with manual verification resulted in less than 1% difference on the average glottal area. These errors mainly come from detection failure in the posterior or anterior parts of the glottal area. Comparisons with automatic threshold-based glottal detection point out the necessity of complete frameworks for automatic detection. The glottovibrogram (GVG), a representation of glottal vibration is also presented. This easily readable representation depicts the time-varying distance of the vocal-fold edges. [Copyright &y& Elsevier]

Objective: To investigate the usefulness of electroglottography (EGG) parameters in the diagnosis and estimation of efficacy of voice therapy for muscle tension dysphonia (MTD). Patients and Methods: Nineteen MTD participants, an equivalent number of dysphonic ('organic') patients with vocal fold lesions and as many normal speakers were enrolled. Acoustic (Ac) and EGG signals during sustained phonation were recorded simultaneously. The period and amplitude perturbation quotient of both signals, the closed quotient (CQ) of EGG signals (mean CQ) and its standard deviation (CQSD) were calculated, and subsequently compared among the three groups. These parameters in the MTD group were compared before and after voice therapy. Results: The perturbation measures of both signals in the MTD group were either as high as or significantly higher than those in the organic group or the control group, respectively. Both the Ac and EGG parameters after therapy significantly decreased. The CQSD, but not mean CQ, also decreased after therapy. Conclusion: EGG parameters related to the regularity of vocal fold vibration, but not to the degree of vocal fold contact (mean CQ), are useful for the diagnosis and estimation of voice therapy outcome in MTD. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

This study examined efficacy of the innate immune defence via the mannose binding lectin (MBL) in a cohort of 55 dystonic patients prospectively referred to the clinic with laryngeal mucosal complaints, who were placed on local steroids (budesonid inhaler, 400 μg 2 times daily) and antihistamines (fexofenadin 180 mg mostly 3 times daily) with adjuvant lifestyle corrections. Treatment efficacy of the larynx was assessed based on mucosal findings of the vocal folds examined with phonatory function studies (PhFS) comprising simultaneous high-speed digital images, kymography, electroglottography and voice acoustics combined with a visual score of arytenoids oedema, as these measures are indicative of the magnitude of laryngitis. Lactose and gluten intolerance and immunological analyses of the innate system were made systematically. Results showed that the genetic aspects of immunology did not reveal a role for the innate immune system, represented by the MBL. But an unexpected positive effect of the larynx treatment on dystonia symptoms was found evidenced by reduction of dystonic complaints and more normative results of PhFS, and a reduction of oedema of the inter arytenoids region. Symptoms relieve and better quality of life was observed on follow-up for the dystonia complaints. [ABSTRACT FROM AUTHOR]

To investigate voice changes as they develop over time due to cigarette smoking, women who never smoked (NS), women who smoked less than 10 years (S1), and women who smoked 10 or more years (S2) were compared. Acoustic (fundamental frequency, jitter, shimmer, signal-to-noise ratio), electroglottographic (open, closing, and speed quotients), aerodynamic (subglottal pressure, airflow, laryngeal airway resistance), and perceptual measures were obtained. Fundamental frequency and open quotient significantly decreased and speed quotient significantly increased in S1 and S2; jitter and shimmer significantly increased in S2 only. NS were perceived as non-smokers more reliably than S1 and S2 as smokers. Fundamental frequency, open quotient, and speed quotient were the most sensitive indicators of smoking effects on the female voice. [ABSTRACT FROM AUTHOR]

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Summary: Vocal fold oscillation patterns in vocal register transitions are still unclarified. The vocal fold oscillations and the open quotient were analyzed with high-speed digital imaging (HSDI) and electroglottography (EGG) in 18 male untrained subjects singing a glissando from modal to the falsetto register. Results reveal that the open quotient changed with register in both HSDI and EGG. The in-class correlations for different HSDI and EGG determinations of the open quotient were high. However, we found only weak interclass correlations between both methods. In 10 subjects, irregularities of vocal fold vibration occurred during the register transition. Our results confirm previous observations that falsetto register is associated with a higher open quotient compared with modal register. These data suggest furthermore that irregularities typically observed in audio and electroglottographic signals during register transitions are caused by irregularities in vocal fold vibration. [Copyright &y& Elsevier]

Dysarthria and phonatory symptomatology are often reported by patients suffering from multiple sclerosis (MS), but have been poorly investigated, although related to life quality. The objective of the study was to investigate the phonatory function in MS patients using objective measures. The speech of 64 MS patients and 64 pair-matched controls was recorded and analyzed using electroglottography, a physiological method that measures the electrical conductance during the opening and closing phases of the vibrating vocal folds. Electroglottographic parameters were correlated with clinical and MRI features. Most of the variables that have been used for the analysis of voice (vocal jitter P = 0.041, standard deviation of the average fundamental frequency P = 0.018, and the mean fundamental frequency of the vibrating vocal folds P = 0.025) differentiated the MS group from the control group. Phonatory function is impaired in MS patients, and physiological methods, such as electroglottography, are useful tools to assess it. [ABSTRACT FROM AUTHOR]

Summary: Languages where phonation type and tone are contrastive make use of extremely fine and controlled actions of laryngeal structures; hence, there is little opportunity to variation in either phonation or pitch. Nonetheless, many American Indian languages have contrastive nonmodal phonation, which, moreover, is subject to a great deal of variation. There are a few studies addressing the phonetics of nonmodal phonation in American Indian languages, and little is known about the phonetics/phonology interface of laryngeal features within the sound patterns of these languages. This article aims to contribute to the knowledge of nonmodal phonation through the detailed study of the phenomenon in Yalálag Zapotec (YZ) and American Indian language. A series of spectral and electrophysiological analyses contribute to the description of YZ nonmodal phonation and its variability across gender. It is argued that the temporal patterns in realization of laryngealization are a property of YZ speaker''s grammar. [Copyright &y& Elsevier]

The authors describe their use of electrolaryngographic (ELG) analysis in four clinical cases: vocal fold lesions (one case); two cases of disordered mobility; and a case with vocal fold structural anomalies. The value of ELG-based analysis is shown both in the description of the pathologies and in the evaluation of the results of surgery. [ABSTRACT FROM AUTHOR]

Summary: The goal of this pilot study was to determine whether the ability to change the degree of posterior glottal adduction (PGA) during phonation can be acquired more easily with the aid of electroglottographic (EGG) real-time feedback. The subject was a 37-year-old untrained female with habitually breathy voice. Before the experiment, she participated in one voice coaching session where exercises for increasing PGA were explained and executed. During the experiment, phonation has been monitored simultaneously with videostroboscopy, electroglottography, and audio recording. While phonating, the subject saw amplitude and period normalized EGG waveform representing one glottal cycle consecutively changing over time. The assignment was to increase the width of the EGG waveform during phonation. Laryngeal imaging revealed a posterior glottal chink during habitual phonation. The subject could only introduce intentional changes into the EGG waveform after its relevance had been explained, and after recapitulation of the exercises of the voice coaching session: An increase of the EGG waveform width coincided with the increase of high-frequency partials and an increase of PGA. For pitches B3 and B4, full glottal closure could be achieved. At G5, a reduction of the posterior glottal chink occurred. The findings of this study suggest that the skill to control the degree of PGA can be acquired, and that EGG real-time feedback can be a crucial element in optimizing the process of skill acquisition, but only if (1) the context and nature of the feedback is explained and (2) proper instructions are provided. The EGG contact quotient might not be sensitive to changes of PGA in falsetto phonation. [Copyright &y& Elsevier]

Phonation threshold pressure (PTP), frequently used for characterizing vocal fold properties, is often difficult to measure. This investigation analyses the lowest pressure initiating vocal fold collision (CTP). Microphone, electroglottograph (EGG), and oral pressure signals were recorded, before and after vocal warm-up, in 15 amateur singers, repeating the syllable /pa:/ at several fundamental frequencies with gradually decreasing vocal loudness. Subglottal pressure was estimated from oral pressure during the p-occlusion, using the audio and the EGG amplitudes as criteria for PTP and CTP. The coefficient of variation was mostly lower for CTP than for PTP. Both CTP and PTP tended to be higher before than after the warm-up. The results support the conclusion that CTP is a promising parameter in investigations of vocal fold characteristics. [ABSTRACT FROM AUTHOR]

Conclusion: A detailed understanding of clinical and voice characteristics will help to differentiate sulcus configuration and plan rational management strategies for each type. Objectives: To investigate the clinical and voice characteristics of patients with sulcus configuration of vocal folds during phonation. Patients and methods: A total of 146 patients with bilateral sulcus configuration of vocal folds were enrolled in this study. Based on videostroboscopic findings, patients were classified into three groups: physiologic sulcus configuration group (type I), pathologic sulcus configuration group, including sulcus vergeture (type II), and sulcus vocalis (type III). Voice analyses were obtained from a recorded speech sample. Results: Thirty-two patients (21.9%) were type I, 61 (41.8%) were type II, and 53 (36.3%) were type III. Different sulcus configuration groups had significantly different roughness and mean fundamental frequency. Type III was significantly different from type I and type II in grade, breathiness, mean flow rate, subglottic pressure, maximum phonation time, Jitter%, and harmonics to noise ratio. The pathologic sulcus showed distinctive features in electroglottograph waveform. [ABSTRACT FROM AUTHOR]

Summary: The incidence of dysphonia in healthy elderly people is high. In individuals with iatrogenic vocal-fold paresis following thyroid surgery, serious aggravation of vocal skills contributes to impaired quality of life and requires proper management. Electroglottography is a common method for providing noninvasive measurements of glottal activity, yielding reliable indicators of glottal closing instants. The purpose of the study was to determine how electroglottography measures change with voice recovery in elderly speakers with vocal-fold palsy, compared with healthy elderly individuals, and which coefficient best represents dysphonia. An electroglottograph with Speech Studio 1.04 software was used to record and analyze the data. Electroglottography data were collected from 12 patients aged 65–78 years (mean=71.3, S.D.=3.8, median=71) and 10 healthy speakers aged 65–77 years (mean=70.9, S.D.=3.9, median=72). The findings show that the distribution of values of % irregularity differs between the groups of patients and controls. % Irregularity and closing quotient significantly correlate with the perceptual degree of dysphonia. Electroglottography can objectify dysphonia in elderly patients with vocal-fold palsy and is a suitable noninvasive tool for tracking the elderly patients’ long-term progress. % Irregularity best represents the vocal-fold dysfunction in elderly patients with a vocal-fold palsy. [Copyright &y& Elsevier]

Summary: This study, focused on the laryngeal source level, introduces the concept of laryngeal vibratory mechanism. Human phonation is characterized by the use of four laryngeal mechanisms, labeled M0–M3, as evidenced by the electroglottographic (EGG) study of the transition phenomena between mechanisms with a population of men and women, trained and untrained singers. Macroscopic and local descriptions of the EGG signal are analyzed during the production of glissandos and held notes with different mechanisms. The transition from one mechanism to another of higher rank is characterized by a jump in frequency, a reduction of EGG amplitude, and a change in the shape of the derivative of the EGG (which may correspond to a reduction of the vibratory mass). These characteristics are used to identify a transition between two mechanisms, in complement with acoustic spectrographic analyses. The pitches of transitions between the two main mechanisms M1 and M2 and the range of the frequency-overlap region are described in detail. The notion of vocal register is revisited in the light of these concepts of laryngeal mechanism. The literature on vocal registers is reviewed, and it is shown that the confusion often cited with respect to this notion may be related to the heterogeneity of the approaches and methods used to describe the phenomena and to the multiplicity of descriptors. Therefore, the terminology of the registers is organized depending on their relation to the four laryngeal vibratory mechanisms. [Copyright &y& Elsevier]

Impedance glottography, or electroglottography, is a noninvasive technique for monitoring the variation of the degree of contact between the vibrating vocal cords during voice production. Electrical impedance is sensed using a pair of electrodes placed on either side of the larynx, by injecting a low-level high-frequency current. A wide-band impedance detector circuit has been developed using a precision rectifier based on voltage feedback clamping amplifier and approximately linear-phase lowpass filter. The circuit can be used for obtaining electroglottogram signal for diagnosis of vocal fold disorders. [ABSTRACT FROM AUTHOR]

Objectives: To use an electroglottography (EGG)-based videostroboscopy tool to assess the anatomical and morphologic characteristics of the pharyngoesophageal (PE) segment in tracheoesophageal (TO) speakers. Study design: Cross-sectional cohort study. Subjects: Fifty-two post-laryngectomy patients with no recurrence and using prosthetic (Blom-Singer) speech. Intervention: An electroglottography (EGG)-based videostroboscopy tool EGG-based rigid videostroboscopy as well as perceptual evaluation. outcome Measures: Stroboscopic protocol included nine subjective/visual parameters to evaluate the neoglottis and study correlation of the G (GRBAS scale) and the overall voice quality (OVQ) with the treatment variables. Results: Of the 52 laryngectomees, videostroboscopic recordings were possible in 46 patients (36 males and 10 females) with a mean age of 63.4 ±10.5 (SD) an electroglottography (EGG)-based videostroboscopy tool years. All used the Blom-Singer valve and the median time since Total Laryngectomy was 2 years. The neoglottis was assessable in 26 patients. We were able to strobe only 9 patients. There was excellent correlation between G and OVQ (Spearman rho > 0.9). Statistically significant correlation was found between G1 and saliva (P = 0.03) and between good OVQ and saliva (P = 0.02); similarly, there was significant correlation between G1 and LVV (P = 0.05) and between good OVQ and LVV (P = 0.03). Conclusions: This study is the first to examine the use of an EGG-based stroboscopy instrument to evaluate TO speech. Our observations suggest that from the standpoint of functional voice, saliva and the LVV had statistically significant effect in determining voice quality. [ABSTRACT FROM AUTHOR]

Summary: To optimize tracheoesophageal (TO) speech after total laryngectomy, it is vital to have a robust tool of assessment to help investigate deficiencies, document changes, and facilitate therapy. We sought to evaluate and validate electroglottography (EGG) as an important tool in the multidimensional assessment of TO speech. This study is a cross-sectional study of the largest cohort of TO speakers treated by a single surgeon. A second group of normal laryngeal speakers served as a control group. EGG analysis of both groups using connected speech and sustained vowels was performed. Two trained expert raters undertook perceptual evaluation using two accepted scales. EGG measures were then analyzed for correlation with treatment variables. A separate correlation analysis was performed to identify EGG measures that may be associated with perceptual dimensions. Our data from EGG analysis are similar to data obtained from conventional acoustic signal analysis of TO speakers. Sustained vowel and connected speech parameters were poorer in TO speakers than in normal laryngeal speakers. In perceptual evaluation, only grade (G) of the GRBAS scale and Overall Voice Quality appeared reproducible and reliable. T stage, pharyngeal reconstruction and method of closure, cricopharyngeal myotomy, and postoperative complications appear to be correlated with the EGG measures. Five voice measures—jitter, shimmer, average frequency, normalized noise energy, and irregularity—correlated well with the key dimensions of perceptual assessment. EGG is an important assessment tool of TO speech, and can now be reliably used in a clinical setting. [Copyright &y& Elsevier]

Summary: The speed with which the vocal folds adduct to the midline is considered an important variable in the etiology of some voice disorders and may also be a meaningful indicator of central or peripheral neural dysfunction. It is proposed that the time lag between the rise of the sound pressure (SP) and electroglottographic (EGG) signals, measured at the onset of phonation, provides a useful index of vocal attack time. This report describes the experimental validation of this measure, whereby the SP and EGG signals were recorded synchronously with high-speed videoendoscopy, from which a digital kymogram was generated. It is shown that, after appropriate signal processing, the intersignal time delay provides a potentially useful measure that varies with vocal attack characteristics. The proposed method calls for no invasive procedures and relies on signals that are routinely obtained in most clinical settings. Unlike acoustic “rise time” measures of voice onset, the glottographic measure involves no operator intervention, requires no arbitrary decisions about measurement points, and may be accomplished quickly and automatically on any personal computer. [Copyright &y& Elsevier]

Summary: The goal of this investigation was to test a new methodology for measuring amplitude modulation (AM) at the level of the vocal folds during vibrato in trained singers, because previous research has suggested that AM arises in large part as an acoustic epiphenomenon through an interaction of the harmonics in the laryngeal source with the resonances of the vocal tract as the fundamental frequency oscillates. A within-subjects model was used to compare vocal activity across three pitch and three loudness conditions. Seventeen female singers with a range of training and experience were recorded with a microphone and an electroglottograph (EGG). Fluctuations in the ratio of closing to opening peaks in the first derivative of the EGG signal were used as an index of laryngeal-level AM. Evidence of laryngeal AM was found to a greater or lesser extent in all the singers, and its extent was not related to the degree of training. Across singers and pitch conditions, it was more prominent at lower intensities. The differentiated EGG signal lends itself to the measurement of AM at the level of the larynx, and the extent of the modulation appears more related to the level of vocal effort than to individual singer characteristics. [Copyright &y& Elsevier]

Summary: Physical modeling using digital waveguide mesh (DWM) models is an audio synthesis method that has been shown to produce an acoustic output in music synthesis applications that is often described as being “organic,” “warm,” or “intimate.” This paper describes work that takes its inspiration from physical modeling music synthesis and applies it to speech synthesis through a physical modeling mesh model of the human oral tract. Oral tract shapes are found using a computational technique based on the principles of biological evolution. Essential to successful speech synthesis using this method is accurate measurements of the cross-sectional area of the human oral tract, and these are usually derived from magnetic resonance imaging (MRI). However, such images are nonideal, because of the lengthy exposure time (relative to the time of articulation of speech sounds) required, the local ambient acoustic noise associated with the MRI machine itself and the required supine position for the subject. An alternative method is described where a bio-inspired computing technique that simulates the process of evolution is used to evolve oral tract shapes. This technique is able to produce appropriate oral tract shapes for open vowels using acoustic and excitation data from two adult males and two adult females, but shapes for close vowels that are less appropriate. This technique has none of the drawbacks associated with MRI, because all it requires from the subject is an acoustic and electrolaryngograph (or electroglottograph) recording. Appropriate oral tract shapes do enable the model to produce excellent quality synthetic speech for vowel sounds, and sounds that involve dynamic oral tract shape changes, such as diphthongs, can also be synthesized using an impedance mapped technique. Efforts to improve performance by reducing mesh quantization for close vowels had little effect, and further work is required. [Copyright &y& Elsevier]

Summary: The aim of this cross-sectional cohort study was to analyze the acoustic, stroboscopic, and perceptual parameters in patients who had undergone vertical partial laryngectomy (VPL) and to compare them with normal subjects (N) and total laryngectomy (TL) patients. This study was carried out in a tertiary referral Cancer Services Centre. We analyzed data from a total of 51 individuals; six VPL patients, 27 TL patients, and 18 N subjects. Acoustic analysis and videostroboscopy were performed using a computerized speech studio. Perceptual analysis was carried out using the GRBAS scoring system. The mean ages in the three groups were 40.9±13.5 (N), 54.3±9.5 (VPL), and 63.9±10.5 years (TL). Acoustic analysis yielded the following results for N, VPL, and TL, respectively: median fundamental frequency (155.2, 224.9, 106.3Hz), shimmer (0.6, 1.9, 1.3dB), and jitter (0.3%, 3.3%, 4.2%). The median maximum phonation time was 21.8 (N), 9.4 (VPL), and 10.3 seconds (TL). The median words per minute (WPM) were 168.5 (N), 126 (VPL), and 127 WPM (TL). Acoustic analysis of VPL voice was significantly different from normal voice (Mann-Whitney, P <0.05) and approximated better to TL parameters. The results of TL and VPL groups show poorer values and larger variability for nearly all the quantitative measures as compared to N subjects. Videostroboscopy demonstrated variable level and amount of closure of the vibrating segment in the reconstructed larynx of the VPL group. VPL GRBAS scores were similar to TL scores with good interrater reliability. The multidimensional assessment of voice in VPL patients is significantly worse than in N subjects and more closely resembles that of patients who have undergone TL with surgical voice restoration. [Copyright &y& Elsevier]

This study was performed to establish the swallowing trigger by using the reaction time from an auditory stimulus. With this stable temporal starting point, we described the chronology of the different acoustic, electrophysiologic, and respiratory events that occurred during swallowing in a population of normal adults. We studied the swallowing reaction time (SRT) in 18 subjects aged 23 to 73 years by using acoustic, electroglottographic (EGG), and aerodynamic recordings. The chronology (the beginning of EGG activity, apnea, and respiratory sound and release) was identified in 91% of the recordings. The average SRT was 264 ms and the average swallowing duration was 977 ms, without any significant difference with respect to gender. The swallowing sound produced during apnea was composed of either two or three components. The reaction time procedure also demonstrated that the first sound component was unstable. By using this procedure for studying swallowing, we were able to stabilize the chronology of the different events, improve the subjects’ attention, and establish a fixed benchmark for performing temporal measurements. [ABSTRACT FROM AUTHOR]

Abstract: Background and purpose: To measure voice outcomes following accelerated hypofractionated radiotherapy for larynx cancer. Materials and methods: Twenty-five patients with T1/T2 glottic cancer underwent serial electroglottographic and acoustic analysis (sustained vowel/i/ and connected speech) before radiotherapy and 1, 6 and 12 months post-treatment. Twenty-five normal subjects served as a reference control population. Results: Pre-treatment measures were significantly worse for larynx cancer patients. Median jitter (0.23% vs 0.97%, p =0.001) and shimmer (0.62dB vs 0.98dB, p =0.05) and differences in data ranges reflected greater frequency and amplitude perturbation in the larynx cancer patients. Pre-treatment Mean Phonation Time (MPT) was significantly reduced (21s vs 14.8s, p =0.002) in larynx cancer patients. There was a trend towards improvement of jitter, shimmer and normalized noise energy at 12 months post-treatment. MPT improved but remained significantly worse than for normal subjects (21s vs 16.4s, p =0.013). Average fundamental frequency resembled normal subjects, including improvement of the measured range (91.4–244.6Hz in controls vs 100–201Hz in post-treatment larynx cancer patients). Conclusions: This non-invasive technique effectively measures post-treatment vocal function in larynx cancer patients. This study demonstrated improvement of many key parameters that influence voice function over 12 months after radiotherapy. [Copyright &y& Elsevier]

Summary: This study was aimed at identifying acoustic and physiological measures useful for monitoring voice changes in postnasopharyngeal patients with nonlaryngeal malignancies, and providing evidences of vocal tract effect on voice through comparisons between individuals with and without intact vocal tract. Simultaneous acoustic-electroglottographic signals recorded during phonation of vowels /i/ and /a/ sustained at habitual, high, and low pitch levels were compared among 10 postradiotherapy patients with nasopharyngeal carcinoma (NPC), 10 voice patients (VPs) with intact vocal tract, and 10 healthy individuals with normal voice (NORM). Results from a series of discriminant analyses revealed that the NPC group generally exhibited lower signal-to-noise (SNR) and open quotient (OQ) and higher Formant 1 frequency (F1) and speed quotient (SQ) than the NORM group. Unlike both VP and NORM groups, the NPC group failed to show a pitch effect on all voice measures, including OQ, SQ, percent jitter, percent shimmer, and SNR, suggesting an effect of radiotherapy and/or vocal tract on laryngeal behaviors. For the vowel /i/, on the other hand, only the NPC and NORM groups showed a pattern of pitch-dependent F1 raising, a reflection of increased pharyngeal narrowing. These findings suggested that the pitch effect on laryngeal behaviors differed not only between individuals with intact vocal tract and those without but also between those with structural and dynamic changes of vocal tract. [Copyright &y& Elsevier]

Twenty-seven total laryngectomy patients (19 males and 8 females) and 18 normal control subjects (10 males and 8 females) were subjected to electroglottography-based single voice recordings using sustained vowels and connected speech. The results showed poorer values and larger variability for all the voice measures for the total laryngectomy patients (TO speech) as compared to that of normal subjects. There were statistically significant differences (p<0.05) for all study parameters between the TO and normal speech. This study shows that robust and reliable data can be obtained using electroglottography in laryngectomees with both a sustained vowel and connected speech. Using these parameters, TO speech is significantly different from normal speech and is highly variable. This methodology has enormous potential for further investigations in laryngectomees and other patients with head and neck cancer. [ABSTRACT FROM AUTHOR]

Purpose: To conduct prospective electroglottographic analyses of voice outcomes after radical chemoradiotherapy for locally advanced laryngopharyngeal cancers and to compare them with patients who have undergone total laryngectomy (TL). Patients and Methods: Twenty-one patients (19 male, 2 female, median age [range] 65 [50–85] years) with Stage III/IV laryngopharyngeal cancer received induction chemotherapy followed by radical chemoradiotherapy. Electroglottography, using the sustained vowel /i/ and connected speech, was performed before treatment and 1, 6, and 12 months after treatment. In addition, single voice recordings were taken from 21 patients (16 male, 5 female, aged 65 [50–84] years) who had undergone TL and surgical voice restoration and from 21 normal controls (18 male, 3 female, aged 65 [33–80] years). Results: Before treatment the vocal measures for the chemoradiotherapy patients were significantly different from normal controls in jitter (p = 0.02), maximum phonation time (MPT) (p = 0.001), and words per minute (WPM) (p = 0.01). At 12 months after treatment MPT and WPM had normalized, but jitter and normalized noise energy were significantly worse than in normal controls. Comparison of voice outcomes at 12 months for chemoradiotherapy patients revealed superiority over the TL group in all parameters except MPT (18.2 s vs. 10.4 s, p = 0.06). Analysis of the recovery of voice up to 12 months after treatment revealed progressive improvement in most electroglottographic measures. Conclusions: This prospective study demonstrates significantly better outcome for patients treated with chemoradiotherapy as compared with TL. Progressive normalization of many voice parameters occurs over the 12 months following chemoradiotherapy. [Copyright &y& Elsevier]

To examine the basis of emotional changes to the voice, physiological and electroglottal measures were combined with acoustic speech analysis of 30 men performing a computer task in which they lost or gained points under two levels of difficulty. Predictions of the main effects of difficulty and reward on the voice were not borne out by the data. Instead, vocal changes depended largely on interactions between gain versus loss and difficulty. The rate at which the vocal folds open and close (fundamental frequency; f 0) was higher for loss than for gain when difficulty was high, but not when difficulty was low. Electroglottal measures revealed that f 0 changes corresponded to shorter glottal open times for the loss conditions. Longer closed and shorter open phases were consistent with raised laryngeal tension in difficult loss conditions. Similarly, skin conductance indicated higher sympathetic arousal in loss than gain conditions, particularly when difficulty was high. The results provide evidence of the physiological basis of affective vocal responses, confirming the utility of measuring physiology and voice in the study of emotion. [ABSTRACT FROM AUTHOR]

Summary: Objectives/Hypothesis: When a soprano, alto, tenor, bass (SATB) quartet sings unaccompanied, or a capella, the members of the group will tend to make use of non-equal-tempered intonation to govern their tuning. If the music they are performing visits different keys and they do maintain non-equal-tempered tuning, then the pitch center will have to shift from its starting point, which is a necessary consequence of the physics behind the use of a non-equal-tempered tuning system. The implication of this shift for tuning in a capella singing is that it is not possible both to maintain accurate non-equal-tempered tuning and to stay in pitch throughout music that modulates in key. Methods: To test this notion, a set of four-part exercises were written by the author that visit several different key chords in sequential progression. In each case, the starting and finishing chords were either identical or exactly an octave apart. Mean fundamental frequency values for each note were measured using four electrolaryngographs (one per singer), and the f0 data were normalized and plotted with respect to equal-tempered tuning to enable any overall tuning shift to be observed. Results: The results indicate that singers do (1) tend to non-equal-tempered tuning and (b) do consequentially shift their intonation with modulation. Conclusions: These data indicate that pitch drift is potentially a necessary part of staying in-tune. Further work is required to identify items in the choral repertoire for which this effect is likely and then to inform the choral conducting and singing communities appropriately. [Copyright &y& Elsevier]

Summary: The aim of this study was to investigate the acoustic and electroglottographic characteristics of patients with mutational dysphonia before and after voice therapy. The clinical records of 15 patients with mutational dysphonia were reviewed, and their voice recordings were analyzed with the help of the Lx Speech Studio program (Laryngograph Ltd, London, UK). After voice therapy combined with the manual compression method, the subjects'' voices lowered in pitch and improved in quality. In addition, we classified the mutational dysphonia into four categories according to the presence of diplophonia and closed quotients. The most common type among the categories was characterized by a bimodal distribution of fundamental frequency (diplophonia), accompanied by a low closed quotient (falsetto voice) at high frequencies. However, the results also showed that mutational dysphonia cannot be generalized as always having a falsetto voice, as shown in other types. The effect of therapy was different for each type, and those cases with both diplophonia and a non-trained falsetto voice could be treated more readily. Consequently, the diplophonia and closed quotient, which were easily analyzed using Lx Speech Studio program, are important factors in the classification of mutational dysphonia. Identification of these characteristics may affect treatment choices, facilitate monitoring of the efficacy of therapy, and aid in estimating prognosis. [Copyright &y& Elsevier]

The results from six published electroglottographic (EGG-based) methods for calculating the EGG contact quotient (CQ EGG ) were compared to closed quotients derived from simultaneous videokymographic imaging (CQ KYM ). Two trained male singers phonated in falsetto and in chest register, with two degrees of adduction in both registers. The maximum difference between methods in the CQ EGG was 0.3 (out of 1.0). The CQ EGG was generally lower than the CQ KYM . Within subjects, the CQ EGG co-varied with the CQkym, but with changing offsets depending on method. The CQ EGG cannot be calculated for falsetto phonation with little adduction, since there is no complete glottal closure. Basic criterion-level methods with thresholds of 0.2 or 0.25 gave the best match to the CQ KYM data. The results suggest that contacting and de-contacting in the EGG might not refer to the same physical events as do the beginning and cessation of airflow. [ABSTRACT FROM AUTHOR]

Background. Our previous findings have indicated that the thyropharyngeal muscles form a retropharyngeal prominence during alaryngeal phonation via the TE fistula. This prominence forms a so-called ‘neoglottis’, which is thought to function as the vibratory source. To better understand the mechanism of TE phonation, we analyzed the vibration of the neoglottis using electroglottography (EGG) and a high-speed digital imaging system . Patients and methods. Two volunteers who use TE phonation for their daily speech communication were subjected to this study. The vibrations of the neoglottis were recorded simultaneously as EGG and high-speed imaging with acoustic signals. Results. The vibrations of the neoglottis, recorded by means of high-speed digital imaging, were exactly synchronized with the waveforms of the acoustic signals and EGG. Conclusions. These results further confirm the neoglottis as the source of vibration during tracheoesophageal (TE) phonation. [ABSTRACT FROM AUTHOR]

Summary: This study was designed to develop a database for the electroglottographic measurement of fundamental frequency (Fo) in normal subjects in running speech, for reference in the diagnosis and follow-up of dysphonic patients. A prospective pilot study included 20 healthy male volunteers without laryngeal disorder. Electroglottographic recordings of speaking Fo during connected speech (French) were obtained from two texts with different prosodic content. Fo histograms were sensitive to the variation of speaking Fo between both texts. Graphic representation of the range and distribution of the Fo of the speaker were designed as normalized Fo histograms with plot lines at 5th and 95th percentiles. Less than 5% variability of Fo histograms was recorded when recording more than 15 subjects. This pilot study designed a graphic display of standardized electroglottographic Fo measurements during the physiological condition of connected speech. As the degree of Fo variability depends on the phonetic contents of the text and on the language spoken, a separate histogram for normal subjects needs to be developed in each country or at least for each voice laboratory, with a standard, previously chosen text. [Copyright &y& Elsevier]

Conclusions . Reinke's edema shows a variety of clinical patterns and differences in voice analysis depending on its type. Electroglottographic measurements help to objectively assess the severity of edema and voice quality before and after surgery. Objectives . Reinke's edema manifests various clinical findings and different voice characteristics depending on the degree of swelling and the severity of voice impairment. The aim of this study was to compare the aerodynamic, acoustic and electroglottographic parameters for the different types of Reinke's edema according to its morphological, perceptual and histopathological classifications, and to assess voice quality in patients with Reinke's edema before and after laryngomicrosurgery. We also aimed to determine which parameter was most associated with the improvement in postoperative voice quality and to investigate the clinical usefulness of electroglottographic analysis in Reinke's edema. Material and methods . The clinical and voice records of 61 patients with Reinke's edema were reviewed. All the patients were classified according to stroboscopic findings (Yonekawa's classification), perceptual grade and histopathological findings. Voice analysis of the perceptual, acoustic, aerodynamic and electroglottographic measurements was carried out using various classifications, and the voices of 23 patients who underwent laryngomicrosurgery were evaluated 2 months after surgery. Furthermore, the voices of 30 normal speakers (controls) were recorded and analyzed. Results . The fundamental frequency (FxM) of Yonekawa Type III was significantly lower than those of the other types of Reinke's edema, and the SD of the FxM, the percentage irregularity of the FxM (CFx) and the percentage irregularity of the amplitude were larger than those of the other types of Reinke's edema. The closed quotient was significantly higher in Yonekawa Type III. In addition, the mean flow rate (MFR), maximum phonation time and harmonics:noise ratio (HNR) differed significantly among the different types of Reinke's edema. The postoperative results showed an increase in the FxM and an improvement in the MFR, subglottic pressure, shimmer and HNR. Correlation analysis showed that jitter, the HNR, the mean closed quotient and the irregularity of the frequency were the parameters that had the best correlation with improvement in postoperative voice quality. [ABSTRACT FROM AUTHOR]

Objective: To demonstrate the variability of electroglottographic measurements of the glottal closed quotient (GCQ) in normal subjects by the calculation method used, fundamental frequency, and intensity. Design: Prospective study. Setting: Tertiary university-based referral center. Subjects: Twenty healthy male volunteers without laryngeal disorder. Three successive sustained productions of the vowel /a/ were performed by each subject. Electroglottographic recordings of GCQ were obtained using the criterion level method, which defines an approximate duration of glottal closure and opening. Glottal closed quotient values were calculated based on criterion levels ranging from 10% to 40%. Main Outcome Measures: The extent of correlation between GCQ variation and the mean fundamental frequency and intensity. Results: As the criterion level increased, a decrease in the mean GCQ was recorded, which was significant with a 10% criterion level increase, up to a critical level of 25%. A significant positive correlation was found between GCQ and the variables of fundamental frequency and intensity. Conclusions: This study demonstrated significant effects of the criterion level used, fundamental frequency, and intensity in the determination of normative values of GCQ. Normative values can only be assessed through the standardization of one criterion level reached by consensus. [ABSTRACT FROM AUTHOR]