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The activation of the musculature of the larynx of six professional trumpeters during performance was analysed using audio, electroglottography (EGG), oxygen saturation, and heart rate signals. Two university trumpet teachers listened to the audio recordings, to evaluate the participants' laryngeal effort during performance. Statistical analysis was performed to explore if there were any correlations between parameters extracted from the EGG data and the responses to the audio stimuli by the listeners. Two hundred and fifty (250) laryngeal articulations were identified where laryngeal raising and effort was observed during trumpet performance. It was not possible to find any correlation between the EGG data and the auditory evaluation results, but both listeners could clearly hear the laryngeal effort. [ABSTRACT FROM AUTHOR]

Voice registers are assumed to be related to different laryngeal adjustments, but objective evidence has been insufficient. While chest register is usually associated with the lower pitch range, and head register with the higher pitch range, here we investigated a professional singer who claimed an ability to produce both these registers at every pitch, throughout her entire singing range. The singer performed separated phonations alternating between the two registers (further called chest-like and head-like) at all pitches from C3 (131 Hz) to C6 (1047 Hz). We monitored the vocal fold vibrations using high-speed video endoscopy and electroglottography. The microphone sound was recorded and used for blind listening tests performed by the three authors (insiders) and by six "naive" participants (outsiders). The outsiders correctly identified the registers in 64% of the cases, and the insiders in 89% of the cases. Objective analysis revealed larger closed quotient and vertical phase differences for the chest-like register within the lower range below G4 (<392 Hz), and also a larger closed quotient at the membranous glottis within the higher range above Bb4 (>466 Hz), but not between Ab4-A4 (415-440 Hz). The normalized amplitude quotient was consistently lower in the chest-like register throughout the entire range. The results indicate that that the singer employed subtle laryngeal control mechanisms for the chest-like and head-like phonations on top of the traditionally recognized low-pitched chest and high-pitched head register phenomena. Across all pitches, the chest-like register was produced with more rapid glottal closure that was usually, but not necessarily, accompanied also by stronger adduction of membranous glottis. These register changes were not always easily perceivable by listeners, however. [ABSTRACT FROM AUTHOR]

Closed quotient (CQ) represents the time ratio for which the vocal folds remain in contact during voice production. Because analyzing CQ values serves as an important reference point in vocal training for professional singers, these values have been measured mechanically or electrically by either inverse filtering of airflows captured by a circumferentially vented mask or postprocessing of electroglottography waveforms. In this study, we introduced a novel algorithm to predict the CQ values only from audio signals. This has eliminated the need for mechanical or electrical measurement techniques. Our algorithm is based on a gated recurrent unit (GRU)-type neural network. To enhance the efficiency, we pre-processed an audio signal using the pitch feature extraction algorithm. Then, GRU-type neural networks were employed to extract the features. This was followed by a dense layer for the final prediction. The Results section reports the mean square error between the predicted and real CQ. It shows the capability of the proposed algorithm to predict CQ values. [ABSTRACT FROM AUTHOR]

In voice analysis, the electroglottographic (EGG) signal has long been recognized as a useful complement to the acoustic signal, but only when the vocal folds are actually contacting, such that this signal has an appreciable amplitude. However, phonation can also occur without the vocal folds contacting, as in breathy voice, in which case the EGG amplitude is low, but not zero. It is of great interest to identify the transition from non-contacting to contacting, because this will substantially change the nature of the vocal fold oscillations; however, that transition is not in itself audible. The magnitude of the cycle-normalized peak derivative of the EGG signal is a convenient indicator of vocal fold contacting, but no current EGG hardware has a sufficient signal-to-noise ratio of the derivative. We show how the textbook techniques of spectral thresholding and static notch filtering are straightforward to implement, can run in real time, and can mitigate several noise problems in EGG hardware. This can be useful to researchers in vocology. [ABSTRACT FROM AUTHOR]

The human voice is notoriously variable, and conventional measurement paradigms are weak in terms of providing evidence for effects of treatment and/or training of voices. New methods are needed that can take into account the variability of metrics and types of phonation across the voice range. The “voice map” is a generalization of the Voice Range Profile (a.k.a. the phonetogram), with the potential to be used in many ways, for teaching, training, therapy and research. FonaDyn is intended as a proof-of concept workbench for education and research on phonation, and for exploring and validating the analysis paradigm of voice-mapping. Version 3.1 of the FonaDyn system adds many new functions, including listening from maps; displaying multiple maps and difference maps to track effects of voice interventions; smoothing/interpolation of voice maps; clustering not only of EGG shapes but also of acoustic and EGG metrics into phonation types; extended multichannel acquisition; 24-bit recording with optional max 140 dB SPL; a built-in SPL calibration and signal diagnostics tool; EGG noise suppression; more Matlab integration; script control; the acoustic metrics Spectrum Balance, Cepstral Peak Prominence and Harmonic Richness Factor (of the EGG); and better window layout control. Stability and usability are further improved. Apple M-series processors are now supported natively.

The activation of the musculature of the larynx of six professional trumpeters during performance was analysed using audio, electroglottography (EGG), oxygen saturation, and heart rate signals. Two university trumpet teachers listened to the audio recordings, to evaluate the participants’ laryngeal effort during performance. Statistical analysis was performed to explore if there were any correlations between parameters extracted from the EGG data and the responses to the audio stimuli by the listeners. Two hundred and fifty (250) laryngeal articulations were identified where laryngeal raising and effort was observed during trumpet performance. It was not possible to find any correlation between the EGG data and the auditory evaluation results, but both listeners could clearly hear the laryngeal effort.

In voice analysis, the electroglottographic (EGG) signal has long been recognized as a useful complement to the acoustic signal, but only when the vocal folds are actually contacting, such that this signal has an appreciable amplitude. However, phonation can also occur without the vocal folds contacting, as in breathy voice, in which case the EGG amplitude is low, but not zero. It is of great interest to identify the transition from non-contacting to contacting, because this will substantially change the nature of the vocal fold oscillations; however, that transition is not in itself audible. The magnitude of the cycle-normalized peak derivative of the EGG signal is a convenient indicator of vocal fold contacting, but no current EGG hardware has a sufficient signal-to-noise ratio of the derivative. We show how the textbook techniques of spectral thresholding and static notch filtering are straightforward to implement, can run in real time, and can mitigate several noise problems in EGG hardware. This can be useful to researchers in vocology.

Even though earlier studies have investigated the relationship between various subjective and instrumental measures of voice, determining a standardized set of voice parameters in evaluating dysphonic voices can help in better diagnostic distinctions and judgment of the treatment outcomes in voice disorders. Thus, the primary objective was to examine the differences in the objective and subjective measures of voice between the participants with dysphonia and participants with a clinically normal voice. The subsequent objective was to identify the group of parameters sensitive to vocal changes in dysphonia using discriminant analysis. Two groups of participants were included in the study. Group 1 comprised of 15 participants with dysphonia. Group 2 included 15 participants with a clinically normal voice. Sustained phonations of vowels were recorded from the participants of both groups and were analyzed perceptually using the GRBAS rating scale. Acoustic, cepstral, spectral, and electroglottographic measures were analyzed from dysphonic voices and normal controls. There were significant differences in both instrumental and perceptual measures between the participants with and without dysphonia. The set of five parameters that were significant predictors that discriminated the dysphonic voice from the clinically normal voice with 100% accuracy was also determined using discriminant analysis. Future investigations on the relation between the specific instrumental and perceptual measures of voice identified in the present study among individuals with various voice disorders can deliver more promising and comprehendible insights into better diagnostic distinctions of voice disorders. [ABSTRACT FROM AUTHOR]

The upper esophageal sphincter (UES) has been reported to show activity during phonation. As it is still unknown whether the phonation-induced UES contraction represents a reflex or a simultaneous activation phenomenon, i.e. co-innervation, this study aims to investigate and characterize the phonation-induced contraction of the UES in healthy individuals by analyzing the influence of various phonation tasks on pressure parameters of the UES. Twenty-five healthy volunteers produced the German neutral vowel [ə] in five different phonation tasks (modal voice, whispering, voiceless speech, creaky voice, and whispery voice). Simultaneously, they underwent high resolution manometry and electroglottography for measurement of pressure parameters in the region of the UES and latencies between larynx and UES activation. During all types of phonation, the maximum pressures of the UES increased significantly (maximum pressure increases of 72%-132%). With regard to mean pressures this was valid for modal voice and whispering (mean pressure increases of 20%-25%). Differences concerning total pressure changes reached statistical significance when comparing whispering and voiceless speech as well as whispery voice. However, differences concerning the total pressure change between modal voices on the one hand and voiceless speech and whispery voice on the other hand turned out to be small. The averaged time delay between larynx and UES activation ranged from approximately -15 ms (whispery voice) to +15 ms (whispering). A phonation induced pressure increase of the UES was confirmed in this study and did exist for different types of phonation. The extent of total pressure changes in the UES increases in relation with laryngeal muscle activity necessary for the phonation type. Next to varying effects of different types of phonation on UES activation, very short latencies indicate that a phonation induced contraction of the UES exists most likely due to co-innervation of UES and laryngeal muscles by the vagus nerve. [ABSTRACT FROM AUTHOR]

Within the scope of semi-occluded vocal tract exercises (SOVTEs), we aimed to examine the effects of four exercise combinations, which involved various fluid densities and tube submersion depths, on acoustic and electroglottographic (EGG) parameters. Four procedures (P) were applied consecutively to 30 female participants with normal voices using different tube submersion depths and fluid densities, including P1 (2 cm, water) , P2 (2 cm, nectar) , P3 (10 cm, water) , and P4 (10 cm, nectar). Nasometric (Nasometer II model 6450) and EGG (Electroglottograph model 6103) measurements were taken before the procedures were initiated (pre-test) and at the end of each procedure. In addition, EGG measurements were taken for each procedure during the application. For all three velar positions (oral passage, oro-nasal passage, nasal passage), the only procedure that caused a significant change compared to the pre-test stage in regard to nasalance score was P2 (2 cm nectar) in common. All other procedures except P1 (2 cm water) significantly increased velar closure compared to pre-test levels. However, when the differences between the exercises were examined, the least velar closure, compared to the other procedures, was obtained after P4 (10 cm nectar). While there was no significant difference between the procedures in the EGG measurements during the exercise, a significantly higher tendency to contact was observed after the procedures with a denser consistency, and an increase in the fundamental frequency (f o) values occurred in the pairwise comparisons of the procedures in the measurements after the exercises. In SOVTEs in which water phonation is performed with a tube, the use of a fluid with a consistency denser than water can be considered a particularly promising approach. In addition, exercises performed with increasing consistencies in 2 cm depth can provide more vocal cord and velopharyngeal port closure by increasing EGG-CQ and nasalance score values. However, more care should be taken while increasing the consistency at a submersion depth of 10 cm. [ABSTRACT FROM AUTHOR]

Featured Application: To "map the voice" means to collate and visualize hundreds of voice measurements per second over a dense grid in fundamental frequency and sound level. This makes it possible to account for the strong influences of these parameters on most voice metrics, influences which otherwise may obscure other effects under investigation. The measurement perspective is changed from a legacy "keyhole" view to a "landscape" view, extending the scientific, clinical and pedagogical reach of voice measurements. Individual acoustic and other physical metrics of vocal status have long struggled to prove their worth as clinical evidence. While combinations of metrics or "features" are now being intensely explored using data analytics methods, there is a risk that explainability and insight will suffer. The voice mapping paradigm discards the temporal dimension of vocal productions and uses fundamental frequency (fo) and sound pressure level (SPL) as independent control variables to implement a dense grid of measurement points over a relevant voice range. Such mapping visualizes how most physical voice metrics are greatly affected by fo and SPL, and more so individually than has been generally recognized. It is demonstrated that if fo and SPL are not controlled for during task elicitation, repeated measurements will generate "elicitation noise", which can easily be large enough to obscure the effect of an intervention. It is observed that, although a given metric's dependencies on fo and SPL often are complex and/or non-linear, they tend to be systematic and reproducible in any given individual. Once such personal trends are accounted for, ordinary voice metrics can be used to assess vocal status. The momentary value of any given metric needs to be interpreted in the context of the individual's voice range, and voice mapping makes this possible. Examples are given of how voice mapping can be used to quantify voice variability, to eliminate elicitation noise, to improve the reproducibility and representativeness of already established metrics of the voice, and to assess reliably even subtle effects of interventions. Understanding variability at this level of detail will shed more light on the interdependent mechanisms of voice production, and facilitate progress toward more reliable objective assessments of voices across therapy or training. [ABSTRACT FROM AUTHOR]

Voice-to-MIDI real-time conversion is a challenging problem that comes with a series of obstacles and complications. The main issue is the tracking of the human voice pitch. Extracting the voice fundamental frequency can be inaccurate and highly computationally exacting due to the spectral complexity of voice signals. In addition, on account of microphone usage, the presence of environmental noise can further affect voice processing. An analysis of the current research and status of the market shows a plethora of voice-to-MIDI implementations revolving around the processing of audio signals deriving from microphones. This paper addresses the above-mentioned issues by implementing a novel experimental method where electroglottography is employed instead of microphones as a source for pitch-tracking. In the proposed system, the signal is processed and converted through an embedded hardware device. The use of electroglottography improves both the accuracy of pitch evaluation and the ease of voice information processing; firstly, it provides a direct measurement of the vocal folds' activity and, secondly, it bypasses the interferences caused by external sound sources. This allows the extraction of a simpler and cleaner signal that yields a more effective evaluation of the fundamental frequency during phonation. The proposed method delivers a faster and less computationally demanding conversion thus in turn, allowing for an efficacious real-time voice-to-MIDI conversion.

Objective: This study aims to investigate the immediate effect of straw phonation on the phonation of Persian-speaking children with repaired cleft palate., Study Design: Quasi-experimental preintervention and postintervention., Methods: Seventeen children with repaired cleft palate and velopharyngeal dysfunction were investigated. A control group was established comprising children without a cleft palate (control group), carefully matched in terms of age and gender. All participants underwent straw phonation and assessment. The assessments were made two times: at baseline and immediately after straw phonation. Each participant performs straw phonation (a short straw measuring 3 mm in inner diameter and 20 cm in length) once for 3 minutes. The acoustic analysis including parameters, such as jitter, shimmer, harmonics-to-noise ratio (HNR), cepstral peak prominence (CPP) parameters, as well as the electroglottography (closed quotient [CQ]) analysis were performed at pretreatment and immediately after treatment., Results: Compared with the pretreatment values, after-treatment observation demonstrated a significant reduction in Jitter % and Shimmer %, and a significant enhancement in HNR and CPP among children with repaired cleft palate. There is no significant difference in intragroup data in the CPP and CQ in pretreatment., Conclusions: The proposed straw phonation technique results in an immediate positive change in the quality of voice in both groups. Moreover, assessments in the clinical group showed a significant decrease in shimmer and jitter perturbation, alongside elevated levels of HNR and CPP subsequent to straw phonation, irrespective of the phonatory task., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

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Objective: Electroglottography (EGG) is an instrumental measurement technique that provides a relative measure of the contact area between vocal folds. It is important to examine whether this measurement provides reliable data in Turkish. The aim of this study is to determine the level of reliability of EGG measurements made at different times related to some sustained vowel vocalizations. Methods: Seventy participants, 35 women and 35 men, aged between 18-25 and who have healthy voice, participated in the study. The Kay-PENTAX Electroglottograph model 6130 was used to study participants' production of/i/,/u/,/ɛ/and/ʌ/vowels. Data were collected from participants at four different time points: (1M) first week in the morning, (1E) first week in the evening, (2M) second week in the morning, and (2E) second week in the evening. The data obtained from all these measurements were matched in terms of time points; 1M-1E, 2M-2E, 1M-2E and 1E-2E. The consistency between measurements of these time points was studied by the inter-class correlation coefficient (ICC), a two-way mixed model. The gender differences of the parameters were analyzed with independent samples t-test. Results: According to repeated test results of all parameters obtained for the/ɛ/vowel for both sexes and the/i/vowel for men only, ICC values were statistically significant at levels ranging from moderate to excellent. In addition, when closed and open phase data were examined, values of all vowels did not differ according to gender during phonations. The frequency periodicity parameter of/ʌ/,/ɛ/and/i/vowels differs statistically significant in this respect. When the averages were examined, it was found that the measurements of women were higher than those of men in all parameters where significant differences were found. Conclusion: As a result of repeated measurements with EGG, regardless of the recording time, measurements of the/ɛ/vowel showed more reliable results compared to other vowels. [ABSTRACT FROM AUTHOR]

Vocal effects - also called extreme or extended vocal techniques - with the intention to sound hoarse or rough are widely used as part of many genres and styles of singing, yet scarcely documented in research. Physiological studies detail the involvement of supraglottic structures for the production of vocal effects, yet the acoustic impact of such involvement has not been documented systematically across phonation types. To report acoustic measurements and electroglottography-specific measurements for the five rough-sounding vocal effects Distortion, Growl, Grunt, Rattle, and Creaking across phonation types to demonstrate differences between notes with and without vocal effects added. Thirty-two professional singers and singing teachers produced sustained vowels in each of the four vocal modes with alternations of adding and removing the vocal effects. The singers were recorded with a microphone at a constant distance as well as with EGG. The vocal effects Distortion, Growl, Grunt, Rattle, and Creaking impact the acoustic spectra in separate and systematic ways across genders and phonation types. Each vocal effect impacted the spectrum in specific and particular frequency regions between 0 and 3.5 KHz as well as in higher partials after 12 kHz with statistical significance. EGG-waveforms were un-impacted by most of the vocal effects produced using supraglottic sound sources, whereas Grunt and Creaking conditions did impact EGG-waveform signals, though not consistently between participants. EGG measures confirmed sustained and unchanged Qx and Fx for most conditions, with statically significant changes in noise measurements Harmonic-to-Noise Ratio, Normalised Noise Energy, Relative Average Perturbation, and Cepstral Peak Prominence, despite Sound Pressure Level differing significantly only for a few specific conditions. Singers scored an average of 5,95 on Voice Handicap Index questionnaires and were all reportedly healthy. Vocal effects added to phonation produce specific increases and specific decreases in particular frequency regions in a systematic way and can be produced in a healthy and sustainable manner, as measured by Voice Handicap Index. Vocal effects can be added to different phonation types with differing acoustic output and singers were able to sustain and control involvement of the supraglottic sound source(s) independently of phonation type. [ABSTRACT FROM AUTHOR]

Subharmonics are an important class of voice signals, relevant for speech, pathological voice, singing, and animal bioacoustics. They arise from special cases of amplitude (AM) or frequency modulation (FM) of the time-domain signal. Surprisingly, to date there is only one open source subharmonics detector available to the scientific community: Sun's subharmonic-to-harmonic ratio (SHR). Here, this algorithm was subjected to a formal evaluation with two data sets of synthesized and empirical speech samples. Both data sets consisted of electroglottographic (EGG) signals, ie, a physiological correlate of vocal fold oscillation that bypasses vocal tract acoustics. Data Set I contained 2560 synthesized EGG signals with varying degrees of AM and FM, fundamental frequency (fo), periodicity, and signal-to-noise ratio (SNR). Data Set II was made up of 25 EGG samples extracted from the CMU Arctic speech data base. For a "ground truth" of subharmonicity, these samples were manually annotated by a group of five external experts. Analysis of the synthesized data suggested that the SHR metric is relatively robust as long as the subharmonic modulation extent is below 0.35 and 0.7 for the FM and AM scenarios, respectively. In the CMU Arctic speech data samples, the SHR analysis reached a maximum sensitivity of about 87% at a specificity of over 90%, but only for adaptive algorithm parameter settings. In contrast, the algorithm's default parameter settings could only successfully classify about 9% of all subharmonic instances. The SHR is a useful metric for assessing the degree of subharmonics contained in voice signals, but only at adaptive parameter settings. In particular, the frequency ceiling should be set to five times the highest fo, and the frame length to at least five times the largest fundamental period of the analyzed signal. For subharmonic classification a threshold of SHR ≥ 0.01 is recommended. [ABSTRACT FROM AUTHOR]

Inspiratory Vocal Fry (IVF) is the voice production during inspiration of a sound with vocal fry perceptual characteristics. The existing scientific literature shows a lack of studies on it. The aim of the study is to highlight anatomical and physiological characteristics of IVF, to assess its effects on spoken and singing voice, to confirm the potential usefulness in speech therapy and vocal pedagogy. Thirty-two healthy subjects (17 male and 15 female) underwent videolaryngostroboscopy to assess the degree of false vocal folds adduction, pharyngeal wall contraction, and degree of vocal folds stretching in different types of phonation: expiratory and inspiratory phonation, Expiratory Vocal Fry (EVF) and IVF. All these parameters were evaluated by a group of three speech therapists and one phoniatrician not belonging to the research group. In addition, for each subject an electroglottography was performed for all the types of phonation previously mentioned, highlighting Contact Quotient (CQ) and Closing/Closed Quotient (CCQ). Three subjects underwent electromyography for a preliminary study of the muscle activation in IVF. False vocal folds adduction (P value = 0.000005) and pharyngeal wall contraction (P value = 0.001155) were significantly reduced in IVF compared to EVF; on the contrary, vocal folds stretching was significantly higher in IVF (P value = 0.000031). Electroglottographic CQ was significantly higher in IVF compared to EVF (P value = 0.019592) and the other types of phonation. Similar results were obtained considering CCQ, as IVF values for this parameter was significantly higher compared to EVF (P value = 0.013062) and expiratory phonation (P value = 0.001324). As regards electromyography, medial thyroarytenoid (TA) motor units were more recruited in IVF, while lateral TA motor units were more recruited in EVF. According to our results, IVF is characterized by higher elastic tension due to a reduced hypertonic contraction of TA muscle and a higher contraction of cricothyroid muscle. Electroglottographic results showed a wider vibratory cycle with an improved massaging effect on vocal folds mucosa. electromyography preliminary analysis confirmed our findings. IVF could be an excellent and useful exercise to reduce muscular hypertonic tension and to facilitate mucosal elasticity. It could be potentially applied in speech therapy approach to dysfunctional and organic dysphonias, post-surgical treatment, in pedagogy and practice of artistic voice. [ABSTRACT FROM AUTHOR]

The phonation types used in the young male role in Kunqu Opera were investigated. Two national young male role singers volunteered as the subjects. Each singer performed three voice conditions: singing, stage speech, and reading lyrics. Three electroglottogram parameters, the fundamental frequency, contact quotient, and speed quotient, were analyzed. Electroglottogram parameters were different between voice conditions. Five phonation types were found by clustering analysis in singing and stage speech: (1) breathy voice, (2) high adduction modal voice, (3) modal voice, (4) untrained falsetto, and (5) high adduction falsetto. The proportion of each phonation type was not identical in singing and stage speech. The relationship between phonation type and pitch was multiple to one in the low pitch range, and one to one in the high pitch range. The sound pressure levels were related to the phonation types. Five phonation types, instead of only the two phonation types (modal voice and falsetto) that are identified in traditional Kunqu Opera singing theory, were concomitantly used in the young male role's artistic voices. These phonation types were more similar to those of the young female roles than to those of the other male roles in the Kunqu Opera. [ABSTRACT FROM AUTHOR]

The application of IT solutions in medicine makes it possible to develop new, more accurate, and noninvasive medical diagnostics. The aim of this study was to propose this kind of solution. It enables the accurate assessment of vocal nodules in children while measuring glottal insufficiency. The input data includes voice and electroglottographic recordings of patients' voices as well as diagnoses made by practitioners. The recordings were parameterized and used to develop a classifier to assess glottal insufficiency of vocal nodules. The classifier was designed with the help of a genetic algorithm. The diagnoses established thanks to the classifier show a 92% agreement with those reached through medical examination. Such effective performance renders the classifier a useful noninvasive screening tool. We compared our method with Deep Neural Network classifier and the Covariance Matrix Adaptation Evolution Strategy (CMA-ES) evolutionary algorithm. The solution that we propose offers a more accurate continuous diagnosis in comparison with the discrete diagnosis of a deep neural network as well as greater accuracy in relation to the CMA-ES algorithm. Another advantage of the proposed solution is the ease with which it can be implemented by healthcare professionals. A Visual Basic for the Applications (VBA) code for LibreOffice macro for the classifier is attached at the end of this paper.

The aim of this paper was to present an analysis of the feasibility of voice quality prediction on the roughness, breathiness, hoarseness (RBH) scale for children with vocal nodules on the basis of both acoustic parameters and electroglottographic (EGG) examination. The first step to achieve this goal involved the creation of a dedicated database, Voice Pathology Analysis Database (VPADB), containing voice recordings from patients, the EGG signal, medical diagnosis, and the classification of voice quality on the above-mentioned scale. The database also contains data concerning the patients' age and sex. The next step involved performing statistical analyses to test the relationship between the values of objective parameters, such as peak slope and normalized amplitude quotient, and the classification of voice quality. The study made use of voice recordings of 57 patients with vocal nodules and 37 healthy individuals. The RBH classification was carried out by two independent voice specialists. It was found that speech signal parameters can be used to predict expert evaluation with regard to roughness and hoarseness.

Abstract Background Late-onset Pompe disease (LOPD) is a metabolic myopathy disorder characterized by progressive muscle damage and among others dysfunction of the voice apparatus, which affects speech and – above all – voice quality. Symptoms include dysphonia, instability, glottic insufficiency, and tense voice. The aim of this study was to evaluate and compare voice quality disorder in a group of 15 LOPD patients who were first examined in 2014 and then re-examined in 2017. Methods In both 2014 and 2017, the same 15 LOPD patients, ranging in age from 15 to 57, from 10 different families, underwent the following examinations: perceptual assessment of voice quality on the RBH scale, electroglottographic recordings, and acoustic recordings. All the patients were on enzyme replacement therapy (ERT). Results Three years after the 2014 study, the LOPD patients demonstrated a deterioration in voice quality. A statistically significant increase in glottic insufficiency (p = 0.0399) and a shift towards tense voice (p = 0.0417) were observed. Two patients – out of three who had received presymptomatic treatment – demonstrated stable voice quality compared with 2014. Conclusions The results suggest increased muscle weakness and progression of LOPD. The parameters Closed Quotient (calculated on the basis of an electroglottographic signal) and Peak Slope (calculated on the basis of an acoustic signal) proved to be the most sensitive.

We provide an update on the state of research on phonation (the production of sound by the vocal folds) since Gordon and Ladefoged's, Journal of Phonetics, 2001 29, 383–406 overview, focusing on the acoustics of breathiness, creak, and other linguistic voice qualities. We highlight cross‐linguistic variation, introduce measuring techniques, and discuss the relationship between phonation and other phonological dimensions (e.g., tone, vowel quality). We also review perceptual literature, an area of phonation research that has greatly expanded recently. Taken together, the studies reviewed demonstrate that phonation types indeed lie not just on a single continuum, but in a multidimensional space. [ABSTRACT FROM AUTHOR]

Context: Semi-occluded vocal tract exercises (SOVTEs) helps to change the acoustic vocal tract impedance in relation to the glottal impedance, improving voice quality. SOVTE has been divided into two groups: steady and fluctuating SOVTEs based on their source of vibration and acoustic characteristics. Aims: The aim of the study was to examine and compare the difference between steady and fluctuating SOVTE with phonation of/a/and/E/on electroglottography and F1–F0 analysis. Settings and Design: Survey design. Study Type: Consort type of study. Materials and Methods: Hundred male participants within the age range of 18–25 years were selected for the study. All the participants were asked to phonate (a) and (E) vowels at a constant pitch for at least 3 s, then all samples were recorded. Assessment of contact quotient percentage value in electroglottography and PRAAT software were used for F1–F0 analysis. Data processing was done on Excel spreadsheet and scoring was processed by SPSS software. Statistical analysis used: One-way analysis of variance (ANOVA) in SPSS Statistics was used for statistical analysis. Results: Mean ± standard deviation and one-way ANOVA revealed that the significant difference was obtained at P < 0.05 in between the steady and fluctuating SOVTEs with phonation of/a/and/E/on EGG parameter and acoustic measure (F1–F0). Conclusions: The study suggested that contact quotient percentage and F1–FO (Hz) value in phonation of/E/are more than/a/. It indicates that phonation of/E/with SOVTEs has more effective in voice disorders than the phonation of/a/and that can be beneficial for treatment of organic voice disorders. [ABSTRACT FROM AUTHOR]

The present study aimed at observing the possible differential effects of eight semioccluded vocal tract exercises (SOVTE) on vocal economy measured by the Quasi Output Cost Ratio (QOCR). Thirty-six participants were included in this study. They were divided into two groups: an experimental group of subjects diagnosed with mild hyperfunctional dysphonia (n = 17) and a control group of vocally healthy subjects (n = 19). Participants were required to randomly select and produce a series of three SOVTE from a list of eight exercises. The electroglottographic based measure QOCR was used to calculate the vocal economy before and after each voice exercise. Significant differences were found when comparing pre and poststages regardless of the vocal condition (normal voice or dysphonia) or the specific SOVTE used. Moreover, when individually comparing the effect of each SOVTE, only tube in water (10 cm) showed significant differences between pre and postconditions (QOCR values were higher after exercises). In general, semioccluded vocal tract exercises tend to increase vocal economy regardless the vocal condition (normal voice or dysphonia) or the specific SOVTE used. Phonation into a tube submerged deep into water promoted the highest increase in vocal economy. An increased acoustic output, nonproportional increase in vocal folds adduction and an effortless voice production would cause this increase in vocal economy after water resistance therapy. [ABSTRACT FROM AUTHOR]

Electroglottography (EGG) is a low-cost, noninvasive technology for measuring changes of relative vocal fold contact area during laryngeal voice production. EGG was introduced about 60 years ago and has gone through a "golden era" of increased scientific attention in the late 1980s and early 90s. During that period, four eminent review papers were written. Here, an update to these reviews is given, recapitulating some earlier landmark contributions and documenting noteworthy developments during the past 25 years. After presenting an algorithmic bibliographic analysis, some methodological aspects pertaining to measurement technology, qualitative and quantitative analysis, and respective interpretation are discussed. In particular, the interpretation of landmarks in the (first derivative of the) EGG waveform is critically examined. It is argued that because of inferior-superior and anterior-posterior phase differences of vocal fold vibration, vocal fold (de)contacting does not occur instantaneously, but over an interval of time. For this reason, instants of vocal fold closing and opening cannot be resolved exactly from the EGG signal. Consequently, any quantitative analysis parameter relying on the determination of (de)contacting events (such as the EGG contact quotient) should be interpreted with care. Finally, recent developments are reviewed for the various fields of application of EGG, including basic voice science and voice production physiology, speech signal processing and classification, clinical practice including swallowing, phonetics, hearing sciences, psychology, singing, trumpet playing, and mammalian and avian bioacoustics. Overall, EGG has over the past six decades developed into a mature technology with a wide range of applications. However, due to current limitations, the full potential of the methodology has as yet not been fully exploited. Future development may occur on three levels: (a) rigorous validation of existent measurement approaches; (b) introduction and rigorous validation of novel quantitative and interpretative approaches; and (c) advancement of the measurement technology itself. [ABSTRACT FROM AUTHOR]

In modern society there is an increased need for verbal communication in many professional categories, in which the voice must be clear, aesthetic and adequately strong. A functionally appropriate voice is estimated to be essential for about one third of current jobs. Nowadays, human communication has acquired impressive social dimensions, with the current technology providing the necessary means of communication, and man generating the message. Phoniatry manages the quality of the verbal transmission. Vocal disorders influence the daily activity of patients, having an impact on their quality of life. In order to identify these conditions as effectively as possible, the authors aim to review the main methods of evaluation and diagnosis of vocal pathology, insisting on their importance and interdependence. For the exact determination of anatomical changes of the vocal folds and for the therapeutic management, laryngeal videoendoscopic examination and videostroboscopy are indispensable. Electroglotography is a diagnostic method complementary to endoscopic techniques, but by no means a substitute. Acoustic examination methods such as computer-assisted techniques for recording complex vocal sounds and analyzing their spectral composition have reached a practicable level that allows their use in the medical offices. [ABSTRACT FROM AUTHOR]

Singing voice is a human quality that requires the precise coordination of numerous kinetic functions and results in a perceptually variable auditory outcome. The use of multi-sensor systems can facilitate the study of correlations between the vocal mechanism kinetic functions and the voice output. This is directly relevant to vocal education, rehabilitation, and prevention of vocal health issues in educators; professionals; and students of singing, music, and acting. In this work, we present the initial design of a modular multi-sensor system for singing voice analysis, and describe its first assessment experiment on the ‘vocal breathiness’ qualitative characteristic. A system case study with two professional singers was conducted, utilizing signals from four sensors. Participants sung a protocol of vocal trials in various degrees of intended vocal breathiness. Their (i) vocal output, (ii) phonatory function, and (iii) respiratory behavior-per-condition were recorded through a condenser microphone (CM), an Electroglottograph (EGG), and thoracic and abdominal respiratory effort transducers (RET), respectively. Participants’ individual respiratory management strategies were studied through qualitative analysis of RET data. Microphone audio samples breathiness degree was rated perceptually, and correlation analysis was performed between sample ratings and parameters extracted from CM and EGG data. Smoothed Cepstral Peak Prominence (CPPS) and vocal folds’ Open Quotient (OQ), as computed with the Howard method (HOQ), demonstrated the higher correlation coefficients, when analyzed individually. DECOM method-computed OQ (DOQ) was also examined. Interestingly, the correlation coefficient of pitch difference between estimates from CM and EGG signals appeared to be (based on the Pearson correlation coefficient) statistically insignificant (a result that warrants investigation in larger populations). The study of multi-variate models revealed even higher correlation coefficients. Models studied were the Acoustic Breathiness Index (ABI) and the proposed multiple regression model CDH (CPPS, DOQ, and HOQ), which was attempted in order to combine analysis results from microphone and EGG signals. The model combination of ABI and the proposed CDH appeared to yield the highest correlation with perceptual breathiness ratings. Study results suggest potential for the use of a completed system version in vocal pedagogy and research, as the case study indicated system practicality, a number of pertinent correlations, and introduced topics with further research possibilities.

Objective: The aim of the study is to investigate the use of incidences and characteristics of Prevocalic Electroglottographic Signal (PVES) derived from electroglottography (EGG) in characterizing glottal stops (GS) in cleft palate speech., Methods: Mandarin nonaspirated monosyllabic first-tone words were used for the speech sampling procedure. A total of 1680 utterances (from 83 patients with repaired cleft palates) were divided into three categories based on the results of auditory-perceptual evaluation of recorded speech sounds by three independent reviewers: [Category A (absence of GS agreed by all three reviewers) (n = 1192 tokens), Category B (two out of three reviewers agreed on the presence of a GS) (n = 181 tokens) and Category C (all three reviewers agreed on the presence of a GS) (n = 307 tokens)]. The EGG signals of the 1680 utterances were analyzed using a MATLAB program to automatically mark the instances of PVES (amplitude and time-interval) in the GS utterances., Results: The result showed that the incidence of EGG PVES presented good positive correlation with auditory-perceptual evaluation (r = 0.703, P＜0.000). Statistical analysis revealed a significant difference in mean PVES amplitude among different groups (P＜0.05). There was a significant distinction in the time interval between groups A and B, as well as in groups A and C (P＜0.05)., Conclusions: The study suggests PVES can be an objective means of identifying GS in cleft palate speech. It also indicates that proportion of amplitude and time interval of PVES tend to be positively correlate with subjective assessment., Competing Interests: Declaration of Competing Interest The authors declare that there is no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Disorders of voice can limit an individual's participation and impair social interaction, thus affecting overall quality of life. Perceptual and objective evaluations can provide the clinician with detailed information regarding voice disorders. Methods: This study comprised 40 subjects aged 34–46 years, 20 of whom (10 male, 10 female) had unilateral vocal fold palsy. Data were obtained for all participants from: the Voice Handicap Index, the grade, roughness, breathiness, asthenia and strain ('GRBAS') scale, acoustic voice analysis, electroglottography, and voice range profiles. Results: The voice evaluations revealed statistically significant (p < 0.05) differences between the controls and study group, both in males and females, pre- and post-therapy. Conclusion: Despite the normalisation of vocal parameters, acoustic, perceptual and self-rated assessments revealed statistically significant differences after therapy. Hence, acoustic measures, namely electroglottographic perturbation, and voice frequency and intensity range, are recommended prior to termination of therapy. [ABSTRACT FROM AUTHOR]

Introduction: The publication describes the characteristics of the glottis in FDs objectified by OQ, measured with VSK and EGG. Aim: The aim of the study was to objectify glottal function in different types of FDs. The scope was to use open quotients gained from various mucosal wave imaging techniques for differential diagnosis of FDs. Material and Method: The study included 204 individuals. In the study, each patient underwent otolaryngological and phoniatric examination. LVS, EGG and VSK were conducted, their results were recorded and stored using an EndoSTROB-DX- -Xion GmbH (Berlin) device with DIVAS software. Results: All patients with FDs had abnormalities in LVS. A statistical analysis showed differences in LVS characteristics according to the type of FD. The mean value of OQVSK was 0.521 in the control group and 0.565 in the study group (P < 0.05). Significant differences were found between patients with hypofunctional - 0.584 and hyperfunctional dysphonia - 0.55. The QOQEGG mean value in patients with FDs was 0.581 and in the control group 0.549 (P < 0.01). There were statistically significant differences between groups of patients with hyper- and hypofunctional dysphonias. Medians amounted to 0.574 and 0.604, respectively. Authors observed different relations of OQ with the type of FD. They decided to introduce a new parameter, illustrating the proportion of QOQEGG/OQVSK. Conclusions: Videostrobokymographic and electroglottographic open quotients differentiate euphony from dysphony. The value of OQVSK and QOQEGG and their proportion varies depending on different types of functional dysphonias. The OQVSK and QOQEGG should be included in the diagnostic algorithm of voice. [ABSTRACT FROM AUTHOR]

Vocal fold nodules are usually caused by voice overuse or vocal hyperfunction, and their symptoms include persistent hoarseness – a disturbance in the vocal fold vibrations which results in a turbulent passage of air in the glottis, manifested as a raspy, rough voice. The aim of the study was to present data concerning voice quality in patients with vocal nodules and to compare electroglottographic analysis (EGG) with acoustic analysis. The study examined 57 children with vocal fold nodules (Group 1). Each patient underwent a phoniatric evaluation of the vocal tract, a videolaryngoscopic examination, and a voice quality assessment, employing electroglottographic and acoustic analyses. The control group consisted of 37 healthy children (Group 2). The following parameters were analyzed: Closed Quotient (EGG signal), Peak Slope, Normalized Amplitude Quotient and Cepstral Peak Prominence (acoustic signal - waveform). Changes in the EGG signal could be detected in 95% of the patients with vocal nodules, indicating the occurrence of vocal nodules and glottal insufficiency. The acoustic analysis confirmed breathy phonation in 63% of the patients. The Closed Quotient parameter proved to be more effective than Peak Slope. Closed Quotient, Peak Slope and Normalized Amplitude Quotient allowed for the differentiation of the EGG signal and the acoustic signal in groups 1 and 2 in a statistically significant way. The results of electroglottographic and acoustic analysis show incorrect voice parameters in patients with vocal nodules with reference to the control group. At the same time, the EGG analysis proved to be more effective than the analysis of the acoustic signal. [ABSTRACT FROM AUTHOR]

Introduction: The diagnostic procedure of phonation is dominated by subjective assessment tools. It seems reasonable to seek methods of quantitative glottal cycle assessment. Objective: The aim of our study was the analysis of open quotients (OQ) of the glottis. Methods: One hundred and twenty-four people were included in the study. Methodology was based on tools available in everyday phoniatrics practice – laryngovideostroboscopy (LVS) and electroglottography (EGG). There were statistically significant differences between control and studied group. Vocal fold polyps, nodules and edema influence glottal function in a different manner, what can be illustrated by objective glottal function parameters. Establishing Videostroboscopic Open Quotient values from three parts of glottis and Electroglottographic Quasi Open Quotient (QOQ) value, can help in dividing patients with benign lesions of vocal folds according to the type of disease. Results and conclusions: Measurement of the open quotient from three parts of the glottis helps to differentially diagnose and localize glottal vocal fold lesions. Videostroboscopic Open Quotient and Electroglottographic QOQ values can be used to quantify the glottal cycle. Videostroboscopic Open Quotient, Electroglottographic QOQ and their ratio varies depending on the type of organic dysphonia. [ABSTRACT FROM AUTHOR]

Fundamental frequency (f o) is often estimated based on electroglottographic (EGG) signals. Because of the nature of the method, the quality of EGG signals may be impaired by certain features like amplitude or baseline drifts, mains hum, or noise. The potential adverse effects of these factors on f o estimation have to date not been investigated. Here, the performance of 13 algorithms for estimating f o was tested, based on 147 synthesized EGG signals with varying degrees of signal quality deterioration. Algorithm performance was assessed through the standard deviation σ fo of the difference between known and estimated f o data, expressed in octaves. With very few exceptions, simulated mains hum, and amplitude and baseline drifts did not influence f o results, even though some algorithms consistently outperformed others. When increasing either cycle-to-cycle f o variation or the degree of subharmonics, the SIGMA algorithm had the best performance (max. σ fo = 0.04). That algorithm was, however, more easily disturbed by typical EGG equipment noise, whereas the NDF and Praat 's auto-correlation algorithms performed best in this category (σ fo = 0.01). These results suggest that the algorithm for f o estimation of EGG signals needs to be selected specifically for each particular data set. Overall, estimated f o data should be interpreted with care. [ABSTRACT FROM AUTHOR]

The phonation types used in the young male role in Kunqu Opera were investigated. Two national young male role singers volunteered as the subjects. Each singer performed three voice conditions: singing, stage speech, and reading lyrics. Three electroglottogram parameters, the fundamental frequency, contact quotient, and speed quotient, were analyzed. Electroglottogram parameters were different between voice conditions. Five phonation types were found by clustering analysis in singing and stage speech: (1) breathy voice, (2) high adduction modal voice, (3) modal voice, (4) untrained falsetto, and (5) high adduction falsetto. The proportion of each phonation type was not identical in singing and stage speech. The relationship between phonation type and pitch was multiple to one in the low pitch range, and one to one in the high pitch range. The sound pressure levels were related to the phonation types. Five phonation types, instead of only the two phonation types (modal voice and falsetto) that are identified in traditional Kunqu Opera singing theory, were concomitantly used in the young male role’s artistic voices. These phonation types were more similar to those of the young female roles than to those of the other male roles in the Kunqu Opera.

Electroglottography (EGG) is a technology developed for measuring the vocal fold contact area during human voice production. Although considered subjective and unreliable as a sole diagnostic method, with the correct application of relevant computational methods, it can constitute a most promising non-invasive voice disorder diagnostic tools in a form of a digital vocal tract pathology classifier. The aim of the following study is to gather and evaluate currently existing digital voice quality assessment systems and vocal tract abnormality classification systems that rely on the use of electroglottographic bio-impedance signals. To fully comprehend the findings of this review, first the subject of EGG is introduced. For that, we summarise most relevant existing research on EGG with a particular focus on its application in diagnostics. Then, we move on to the focal point of this work, which is describing and comparing the existing EGG-based digital voice pathology classification systems. With the application of PRISMA model, 13 articles were chosen and analysed in detail. Direct comparison between chosen studies brought us to pivotal conclusions, which have been described in Section 5 of this report. Meanwhile, certain limitations arising from the literature were identified, such as questionable understanding of the nature of EGG bio-impedance signals. The appropriate recommendations for future work were made, including the application of different methods for EGG feature extraction, as well as the need for continuous EGG datasets development containing signals gathered in various conditions and with different equipments., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

The objective of this study was to determine the relationship between lung volume (LV) conditions and vocal fold vibratory patterns using measurements of closed quotient (CQ), fundamental frequency (F0) and relative vocal intensity. Forty-three healthy and vocally untrained females were asked to produce the vowel /a/ following breathing instructions that cued for higher, habitual, or lower LV conditions. Closed quotient was measured by electroglottography (EGG) and analyzed using criterion-level method of 25%. An average of CQ, F0 and relative vocal intensity were obtained. No significant difference was observed in CQ between cued LV conditions; however, there was a trend for CQ to increase in the cued high LV condition. Relative vocal intensity and F0 differed significantly across all conditions with higher F0 and relative vocal intensity observed at the high LV condition. These findings suggested that the use of different cued LVs did not have a significant impact on CQ. This may have been due to (1) the phonatory task, (2) variability in responses to the breathing instructions between individuals, and (3) the measurement of CQ. However, F0 and relative vocal intensity were significantly influenced by the LV. This offers a possible alternative approach in cueing pitch and loudness in singing and voice therapy. [ABSTRACT FROM AUTHOR]

Introduction: Electroglottography (EGG) is the most commonly used method of indirect visual examination of vocal fold vibration.Aim: The study was conducted with an aim of assessing EGG quasi open quotient (QOQEGG) in different functional dysphonias to develop a differential diagnosis. The second aim was to check the influence of articulation on QOQEGG values.Material and methods: There were 20 people without voice problems, 20 patients with hypofunctional dysphonia and 20 patients with hyperfunctional dysphonia included in the study. Electroglottography was recorded during comfortable sustained phonation of [a], [e], [i], [o], [u].Results: There were no statistically significant differences in QOQEGG observed during phonation of different vowels in the control group and patients with hyperfunctional dysphonia. In patients with hypofunctional dysphonia, significantly higher values of QOQEGG were observed during [a] and [e]. Both in the control and in studied groups vowel [i] was vocalized significantly quieter.Conclusions: To conclude, EGG can be useful in differential diagnosis of functional dysphonia. QOQEGG is a parameter differentiating hypofunctional dysphonia from hyperfunctional dysphonia. Dissimilarities in articulation of different vowels in patients with various types of dysphonia influence values of QOQEGG. EGG study protocol in cases of functional dysphonia should include a comparison of [a], [e], [i] vowels. [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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Accurate determination of glottal instants and electroglottographic (EGG) parameters is most important in voice pathology analysis including multiple voice disorders: neurological, functional, and laryngeal diseases. In this paper, we present a new effective method for reliable detection of glottal instants and EGG parameters from an EGG signal composed of voiced and nonvoice segments. In the first stage, we present an adaptive variational mode decomposition based algorithm for suppressing low-frequency artifacts and additive high-frequency noises. Based upon mode center frequency criterion, the proposed method first constructs a candidate EGG feature signal for determination of glottal closure and opening instants. In the second stage, the candidate glottal instants are determined by detecting the positive and negative zerocrossings in normalized candidate EGG feature signal, respectively. Finally, an autocorrelation features based postprocessing algorithm is presented to reject nonglottal instants from the nonspeech production segments. The accuracy and robustness of the method is tested using noise-free and noisy EGG signals. Evaluation results show that the proposed method achieves an average overall accuracy of 95.06%, identification rate of 95.34%, missed rate of 3.60%, and false alarm rate of 0.06% with average absolute identification error of 0.71 ± 0.66 ms for an SNR of 15 dB. Results demonstrate that the proposed method significantly outperforms the other existing methods under both noise-free and noisy EGG signals. [ABSTRACT FROM PUBLISHER]