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Objectives: This study aims to explore the effects of thyroidectomy—a surgical intervention involving the removal of the thyroid gland—on voice quality, as represented by acoustic and electroglottographic measures. Given the thyroid gland's proximity to the inferior and superior laryngeal nerves, thyroidectomy carries a potential risk of affecting vocal function. While earlier studies have documented effects on the voice range, few studies have looked at voice quality after thyroidectomy. Since voice quality effects could manifest in many ways, that a priori are unknown, we wish to apply an exploratory approach that collects many data points from several metrics. Methods: A voice-mapping analysis paradigm was applied retrospectively on a corpus of spoken and sung sentences produced by patients who had thyroid surgery. Voice quality changes were assessed objectively for 57 patients prior to surgery and 2 months after surgery, by making comparative voice maps, pre- and post-intervention, of six acoustic and electroglottographic (EGG) metrics. Results: After thyroidectomy, statistically significant changes consistent with a worsening of voice quality were observed in most metrics. For all individual metrics, however, the effect sizes were too small to be clinically relevant. Statistical clustering of the metrics helped to clarify the nature of these changes. While partial thyroidectomy demonstrated greater uniformity than did total thyroidectomy, the type of perioperative damage had no discernible impact on voice quality.ConclusionsChanges in voice quality after thyroidectomy were related mostly to increased phonatory instability in both the acoustic and EGG metrics. Clustered voice metrics exhibited a higher correlation to voice complaints than did individual voice metrics., QC 20240508

This work investigates the effect of body position on voice quality, based on cepstral peak prominence (CPP) and spectrum balance (SB) metrics layered on a mapped speech range profile (SRP) across a sound pressure level (SPL) and fundamental frequency (fo) plane. Eight participants were tested in an upright position, supine position at 0º and an inverted position at -10º. Findings show varied and small changes in voice quality in connected speech between positions and that effects may occur at specific SPL and fo ranges among some participants., This conference paper is a summary of the lead author's Bachelor thesis, which can be found at https://www.diva-portal.org/smash/record.jsf?dswid=6218&pid=diva2%3A1768562QC 20240902

We can make many different sounds with our voices, communicating not only with what is said, but also in which context it is said, and who is saying it. This large variability makes the voice a rich channel for communication, but it also presents us with challenges when we try to assess the status of a voice using quantitative measurements, rather than by listening. When voices run into trouble, even more variability can be expected. Voice production is usually described as three processes in sequence: respiration /€“ breathing; phonation /€“ the vibration of the vocal folds; and articulation /“ changing the shape of the vocal tract, which modifies the sound into vowels and consonants. For brevity, let’s look only at some aspects of phonation that can be expected to be clinically relevant., This is a short article intended as outreach to an interested general audience.QC 20240815

Objectives: This study aims to explore the effects of thyroidectomy—a surgical intervention involving the removal of the thyroid gland—on voice quality, as represented by acoustic and electroglottographic measures. Given the thyroid gland's proximity to the inferior and superior laryngeal nerves, thyroidectomy carries a potential risk of affecting vocal function. While earlier studies have documented effects on the voice range, few studies have looked at voice quality after thyroidectomy. Since voice quality effects could manifest in many ways, that a priori are unknown, we wish to apply an exploratory approach that collects many data points from several metrics. Methods: A voice-mapping analysis paradigm was applied retrospectively on a corpus of spoken and sung sentences produced by patients who had thyroid surgery. Voice quality changes were assessed objectively for 57 patients prior to surgery and 2 months after surgery, by making comparative voice maps, pre- and post-intervention, of six acoustic and electroglottographic (EGG) metrics. Results: After thyroidectomy, statistically significant changes consistent with a worsening of voice quality were observed in most metrics. For all individual metrics, however, the effect sizes were too small to be clinically relevant. Statistical clustering of the metrics helped to clarify the nature of these changes. While partial thyroidectomy demonstrated greater uniformity than did total thyroidectomy, the type of perioperative damage had no discernible impact on voice quality.ConclusionsChanges in voice quality after thyroidectomy were related mostly to increased phonatory instability in both the acoustic and EGG metrics. Clustered voice metrics exhibited a higher correlation to voice complaints than did individual voice metrics., QC 20240508

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., QC 20240513

Objectives: This study aims to explore the effects of thyroidectomy—a surgical intervention involving the removal of the thyroid gland—on voice quality, as represented by acoustic and electroglottographic measures. Given the thyroid gland's proximity to the inferior and superior laryngeal nerves, thyroidectomy carries a potential risk of affecting vocal function. While earlier studies have documented effects on the voice range, few studies have looked at voice quality after thyroidectomy. Since voice quality effects could manifest in many ways, that a priori are unknown, we wish to apply an exploratory approach that collects many data points from several metrics. Methods: A voice-mapping analysis paradigm was applied retrospectively on a corpus of spoken and sung sentences produced by patients who had thyroid surgery. Voice quality changes were assessed objectively for 57 patients prior to surgery and 2 months after surgery, by making comparative voice maps, pre- and post-intervention, of six acoustic and electroglottographic (EGG) metrics. Results: After thyroidectomy, statistically significant changes consistent with a worsening of voice quality were observed in most metrics. For all individual metrics, however, the effect sizes were too small to be clinically relevant. Statistical clustering of the metrics helped to clarify the nature of these changes. While partial thyroidectomy demonstrated greater uniformity than did total thyroidectomy, the type of perioperative damage had no discernible impact on voice quality.ConclusionsChanges in voice quality after thyroidectomy were related mostly to increased phonatory instability in both the acoustic and EGG metrics. Clustered voice metrics exhibited a higher correlation to voice complaints than did individual voice metrics., QC 20240508

Objectives: This study aims to explore the effects of thyroidectomy—a surgical intervention involving the removal of the thyroid gland—on voice quality, as represented by acoustic and electroglottographic measures. Given the thyroid gland's proximity to the inferior and superior laryngeal nerves, thyroidectomy carries a potential risk of affecting vocal function. While earlier studies have documented effects on the voice range, few studies have looked at voice quality after thyroidectomy. Since voice quality effects could manifest in many ways, that a priori are unknown, we wish to apply an exploratory approach that collects many data points from several metrics. Methods: A voice-mapping analysis paradigm was applied retrospectively on a corpus of spoken and sung sentences produced by patients who had thyroid surgery. Voice quality changes were assessed objectively for 57 patients prior to surgery and 2 months after surgery, by making comparative voice maps, pre- and post-intervention, of six acoustic and electroglottographic (EGG) metrics. Results: After thyroidectomy, statistically significant changes consistent with a worsening of voice quality were observed in most metrics. For all individual metrics, however, the effect sizes were too small to be clinically relevant. Statistical clustering of the metrics helped to clarify the nature of these changes. While partial thyroidectomy demonstrated greater uniformity than did total thyroidectomy, the type of perioperative damage had no discernible impact on voice quality.ConclusionsChanges in voice quality after thyroidectomy were related mostly to increased phonatory instability in both the acoustic and EGG metrics. Clustered voice metrics exhibited a higher correlation to voice complaints than did individual voice metrics., QC 20240508

Objectives: This study aims to explore the effects of thyroidectomy—a surgical intervention involving the removal of the thyroid gland—on voice quality, as represented by acoustic and electroglottographic measures. Given the thyroid gland's proximity to the inferior and superior laryngeal nerves, thyroidectomy carries a potential risk of affecting vocal function. While earlier studies have documented effects on the voice range, few studies have looked at voice quality after thyroidectomy. Since voice quality effects could manifest in many ways, that a priori are unknown, we wish to apply an exploratory approach that collects many data points from several metrics. Methods: A voice-mapping analysis paradigm was applied retrospectively on a corpus of spoken and sung sentences produced by patients who had thyroid surgery. Voice quality changes were assessed objectively for 57 patients prior to surgery and 2 months after surgery, by making comparative voice maps, pre- and post-intervention, of six acoustic and electroglottographic (EGG) metrics. Results: After thyroidectomy, statistically significant changes consistent with a worsening of voice quality were observed in most metrics. For all individual metrics, however, the effect sizes were too small to be clinically relevant. Statistical clustering of the metrics helped to clarify the nature of these changes. While partial thyroidectomy demonstrated greater uniformity than did total thyroidectomy, the type of perioperative damage had no discernible impact on voice quality.ConclusionsChanges in voice quality after thyroidectomy were related mostly to increased phonatory instability in both the acoustic and EGG metrics. Clustered voice metrics exhibited a higher correlation to voice complaints than did individual voice metrics., QC 20240508

The human voice is the most common `carrier' of speech, but how does linguistic voice quality affect speech production and perception? Typical `modal' voice possesses a single fundamental frequency (f0), identified as the voice's pitch. Period doubling, known as a commonly-occurring type of creaky voice, consists of alternating glottal pulses with different periods and/or amplitudes for which multiple fundamental frequencies (f0s) co-exist. Thus, the pitch during period doubling is often indeterminate, and so it is unclear whether linguistic tone is identifiable, and how linguistic tone is identified, in this voice. Although period doubling has been mostly studied in voice disorders and singing styles, it frequently occurs in non-pathological voices, and its defining characteristics remain to be determined.This dissertation contributes three studies to characterize the physical, distributional, and perceptual aspects of period-doubled voice. Simultaneous electroglottography (EGG) and audio recordings of a Mandarin read speech corpus were analyzed to capture properties of the articulation and acoustics of period doubling in Chapters 2 and 3; artificial language learning and shadowing experimentation were used to probe perception of period doubling in Chapter 4.The EGG study in Chapter 2 finds that period doubling is articulated as two alternating pulses with distinct pitches as well as voice qualities. Specifically, I show that the glottal cycles in period doubling are not generally constricted, but instead oscillate between degrees of constriction shown by alternating contact quotients, pulse shape, and speed of vocal fold contact. This in addition to the alternating frequencies likely leads to the indeterminate pitch and quality percept in period doubling. The results also pose challenges to the existing taxonomy of creaky voice subtypes based on the established acoustic attributes.The acoustic analysis in Chapter 3 finds that period doubling is characterized acous

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., QC 20221215

Introduction. Teachers are occupational voice users with high risk of developing vocal pathologies due to their work. To face this situation, it is common the use of semi-occluded vocal tract (SOVT) exercises, a strategy of voice education/rehabilitation implemented to induce a change in the vibration pattern of the vocal folds, mitigating, therefore, the risk of vocal lesion by reducing the collision stress applied to tissues. A variety of reports have indicated that this treatment has effects in the closed quotient (CQ), an indirect measure of collision stress. Aim. The purpose of this study was to examine the physiological effect of two different SOVT exercises in larynx activity of teachers with constant vocal effort but without vocal pathology. Methods. 43 samples of teachers were recorded before, during and after executing two SOVT exercises (tongue trill and tube phonation). Electroglottographic samples were analyzed in order to obtain CQ. Results and conclusion. Both exercises had a significant difference of CQ scores when before and during conditions were compared. Any difference was found on this parameter after executing the activity. These findings agree with previous reports where CQ tends to increase during phonation through resonance tubes; on the contrary, execution of tongue trill tends to decrease CQ values. This behavior might be because of the particular biomechanical mechanisms of each exercise., Introducción. Los docentes son usuarios ocupacionales de la voz con alto riesgo de desarrollar patologías vocales a causa de su labor. Para enfrentar esta problemática, suelen usarse ejercicios con tracto vocal semiocluido (TVSO), estrategia de educación/rehabilitación empleada para generar un cambio en el patrón de vibración de los pliegues vocales, minimizando el riesgo de lesión vocal al reducir el estrés de colisión al que se someten los tejidos. Diversos reportes han indicado que este tratamiento tiene efectos en el cociente de cierre (CQ), medida indirecta del estrés de colisión. Objetivo. Examinar el efecto fisiológico de dos ejercicios con TVSO en la actividad laríngea de profesores con esfuerzo vocal constante pero sin patología vocal. Metodología. Se registraron muestras de 43 profesores antes, durante y después de la realización de dos ejercicios con TVSO (vibración lingual y fonación en tubos). Las muestras de electroglotografía se analizaron para obtener el CQ. Resultados y conclusión. Se observó una diferencia significativa al comparar los valores del CQ antes y durante la realización de ambos ejercicios. No se encontraron cambios en este parámetro después de ejecutar la actividad. Estos hallazgos concuerdan con reportes previos en los cuales el CQ tiende a aumentar durante la fonación en tubos; contrariamente, la realización de la vibración lingual tiende a decrecer el valor del CQ. Es posible que este comportamiento se deba a los mecanismos biomecánicos particulares de cada ejercicio.

Electromyography and electroglottography are exploration techniques that, combined with biofeedback, enable muscle adjustments in the issuer to improve phonatory function. We therefore intend to determine the effects of electrographic biofeedback to increase or decrease the tone in the muscles that involves indirectly or directly in the production of the voice, to identify the effects of electroglottographic biofeedback to produce changes in the vibratory pattern of the vocal folds and, finally, to determine the frequency of biofeedback in vocal treatment, starting from systematic review in papers published since 2000 in speech therapy and laryngological journals. The analysis of the studies obtained in the documentation process suggests that the use of electromyographic and electroglottographic biofeedback can produce lasting changes over time in the vibratory pattern of vocal folds and in the muscle activity of vocal production, so that could be a useful instrument added to vocal intervention based on evidence. The data in relation to frequency of use of this instrument, however, does not seem conclusive., La electromiografía y electroglotografía son técnicas de exploración que, combinadas con el biofeedback, permiten en el emisor ajustes musculares para la mejora de la función fonatoria. Nos proponemos, pues, determinar los efectos del biofeedback electromiográfico para aumentar o disminuir el tono en los músculos que intervienen de manera indirecta o directa en la producción de la voz, identificar los efectos del biofeedback electroglográfico para producir cambios en el patrón vibratorio de los pliegues vocales y, finalmente, determinar la frecuencia del biofeedback en el tratamiento vocal, a partir de una revisión sistemática de los trabajos publicados desde el año 2000 en revistas logopédicas y laringológicas. El análisis de los estudios obtenidos en el proceso de documentación sugiere que el uso del biofeedback electromiográfico y electroglotográfico puede producir cambios perdurables en el tiempo sobre el patrón vibratorio de los pliegues vocales y en la actividad muscular de la producción vocal, de manera que podría ser un instrumento útil añadido a la intervención vocal basadaen la evidencia. Los datos relativos a la frecuencia de uso necesaria de este instrumento, sin embargo, no parecen concluyentes.

Objectives: To confirm the data reported in our previous studies on the analysis of the variability of the electroglottographic signal in the pathological voice; to evaluate possible differences in variability between organic and functional pathologies; to identify any distinctive/typical EGG patterns for these pathologies. Methods: One hundred twenty-five subjects were enrolled (36 euphonic and 89 pathological: 24 functional dysphonia, 21 bilateral vocal nodules, 23 unilateral polyps and 21 unilateral cysts). All subjects were studied with videolaryngostroboscopy, spectrographic analysis of voice and electroglottography (EGG). The EGG signal variability was then investigated using amplitude-speed combined analysis, by means of a proprietary software algorithm. Amplitude and Speed variation were expressed as a new parameter, the Variability Index (VI), calculated both for the whole EGG signal recorded (VI-tot) and in each phase of the glottic cycle (VI-Q, absolute value; VI-Q%, percentage value). Results: In the comparison of VI values between pathological and normal groups, VI-tot and VI-Q2% (which corresponds to the final phase of vocal fold contact) were significantly greater in pathological subjects (P= 0.002). The comparison of VI values among subgroups of the various pathologies showed a difference for VI-tot (P< 0.0001) and VI-Q2% (P= 0.001); this difference was more marked in the cysts than in the functional dysphonia. The cut-off values of VI-tot and VI-Q2% were 0.191 and 18.17%, respectively (sensitivity and specificity 65.2% and 66.7% for VI-tot and 84.3% and 77.8% for VI-Q2%). Conclusions: The variability of the EGG signal investigated through the combined analysis of the amplitude and the speed of vibration using a proprietary algorithm software has proved useful not only to distinguish the normal voice from the pathological voice, but also to characterize which phases are more altered in the various voice pathologies studied, both functional and org

Purpose: The purpose of this study is to identify the extent to which various measurements of contacting parameters differ between children and adults during habitual range and overlap vocal frequency/intensity, using voice map–based assessment of noninvasive electroglottography(EGG). Method: EGG voice maps were analyzed from 26 adults(22–45 years) and 22 children (4–8 years) during connected speech and vowel /a/ over the habitual range and the overlap vocal frequency/intensity from the voice range profile task on the vowel /a/. Mean and standard deviations of contact quotient by integration, normalized contacting speed, quotient of speed by integration, and cycle-rate sample entropy were obtained. Group differences were evaluated using the linear mixed model analysis for the habitual range connected speech and the vowel, whereas analysis of covariance was conducted for the overlap vocal frequency/intensity from the voice range profile task. Presence of a “knee” on the EGG wave shape was determined by visual inspection of the presence of convexity along the decontacting slope of the EGG pulse and the presence of the second derivative zero-crossing. Results: The contact quotient by integration, normalized contacting speed, quotient of speed by integration, and cycle-rate sample entropy were significantly different in children compared to (a) adult males for habitual range and(b) adult males and adult females for the overlap vocal frequency/intensity. None of the children had a “knee” on the decontacting slope of the EGG slope. Conclusion: EGG parameters of contact quotient by integration, normalized contacting speed, quotient of speed by integration, cycle-rate sample entropy, and absence of a “knee” on the decontacting slope characterize the waveshape differences between children and adults, whereas the normalized contacting speed, quotient of speed by integration, cycle-rate sample entropy, and presence of a “knee” on the downward pulse slope characterize the waves, QC 20210813

Objectives: To determine if in singing there is an effect of lung volume on the electroglottographic waveform, and if so, how it varies over the voice range. Study design: Eight trained female singers sang the tune “Frère Jacques” in 18 conditions: three phonetic contexts, three dynamic levels, and high or low lung volume. Conditions were randomized and replicated. Methods: The audio and EGG signals were recorded in synchrony with signals tracking respiration and vertical larynx position. The first 10 Fourier descriptors of every EGG cycle were computed. These spectral data were clustered statistically, and the clusters were mapped by color into a voice range profile display, thus visualizing the EGG waveform changes under the influence of fo and SPL. The rank correlations and effect sizes of the relationships between relative lung volume and several adduction-related EGG wave shape metrics were similarly rendered on a color scale, in voice range profile-style ʻvoice maps.ʼ Results: In most subjects, EGG waveforms varied considerably over the voice range. Within subjects, reproducibility was high, not only across the replications, but also across the phonetic contexts. The EGG waveforms were quite individual, as was the nature of the EGG shape variation across the range. EGG metrics were significantly correlated to changes in lung volume, in parts of the range of the song, and in most subjects. However, the effect sizes of the relative lung volume were generally much smaller than the effects of fo and SPL, and the relationships always varied, even changing polarity from one part of the range to another. Conclusions: Most subjects exhibited small, reproducible effects of the relative lung volume on the EGG waveform. Some hypothesized influences of tracheal pull were seen, mostly at the lowest SPLs. The effects were however highly variable, both across the moderately wide fo-SPL range and across subjects. Different singers may be applying different techniques and comp, QC 20200703

Objectives: To determine if in singing there is an effect of lung volume on the electroglottographic waveform, and if so, how it varies over the voice range. Study design: Eight trained female singers sang the tune “Frère Jacques” in 18 conditions: three phonetic contexts, three dynamic levels, and high or low lung volume. Conditions were randomized and replicated. Methods: The audio and EGG signals were recorded in synchrony with signals tracking respiration and vertical larynx position. The first 10 Fourier descriptors of every EGG cycle were computed. These spectral data were clustered statistically, and the clusters were mapped by color into a voice range profile display, thus visualizing the EGG waveform changes under the influence of fo and SPL. The rank correlations and effect sizes of the relationships between relative lung volume and several adduction-related EGG wave shape metrics were similarly rendered on a color scale, in voice range profile-style ʻvoice maps.ʼ Results: In most subjects, EGG waveforms varied considerably over the voice range. Within subjects, reproducibility was high, not only across the replications, but also across the phonetic contexts. The EGG waveforms were quite individual, as was the nature of the EGG shape variation across the range. EGG metrics were significantly correlated to changes in lung volume, in parts of the range of the song, and in most subjects. However, the effect sizes of the relative lung volume were generally much smaller than the effects of fo and SPL, and the relationships always varied, even changing polarity from one part of the range to another. Conclusions: Most subjects exhibited small, reproducible effects of the relative lung volume on the EGG waveform. Some hypothesized influences of tracheal pull were seen, mostly at the lowest SPLs. The effects were however highly variable, both across the moderately wide fo-SPL range and across subjects. Different singers may be applying different techniques and comp, QC 20200703

Objectives: To determine if in singing there is an effect of lung volume on the electroglottographic waveform, and if so, how it varies over the voice range. Study design: Eight trained female singers sang the tune “Frère Jacques” in 18 conditions: three phonetic contexts, three dynamic levels, and high or low lung volume. Conditions were randomized and replicated. Methods: The audio and EGG signals were recorded in synchrony with signals tracking respiration and vertical larynx position. The first 10 Fourier descriptors of every EGG cycle were computed. These spectral data were clustered statistically, and the clusters were mapped by color into a voice range profile display, thus visualizing the EGG waveform changes under the influence of fo and SPL. The rank correlations and effect sizes of the relationships between relative lung volume and several adduction-related EGG wave shape metrics were similarly rendered on a color scale, in voice range profile-style ʻvoice maps.ʼ Results: In most subjects, EGG waveforms varied considerably over the voice range. Within subjects, reproducibility was high, not only across the replications, but also across the phonetic contexts. The EGG waveforms were quite individual, as was the nature of the EGG shape variation across the range. EGG metrics were significantly correlated to changes in lung volume, in parts of the range of the song, and in most subjects. However, the effect sizes of the relative lung volume were generally much smaller than the effects of fo and SPL, and the relationships always varied, even changing polarity from one part of the range to another. Conclusions: Most subjects exhibited small, reproducible effects of the relative lung volume on the EGG waveform. Some hypothesized influences of tracheal pull were seen, mostly at the lowest SPLs. The effects were however highly variable, both across the moderately wide fo-SPL range and across subjects. Different singers may be applying different techniques and comp, QC 20200703

Developmentally, children do not have five well-defined layers of the vocal folds as adults. Also, children are often less able to tolerate the invasiveness of endoscopy. Electroglottography (EGG) is not invasive, but little is known of how the EGGs of children differs from those of adults. The goal of this study was to quantify some differences in the shape of the EGG waveform between children and adults, while accounting for the sensitivity to variation in the independent variables fo and SPL. A novel mapping of EGG waveform parameters over the speech and voice ranges was employed, QC 20210611

The quest for objective physical criteria for normal or aberrant voice has so far been disappoint-ing; on the whole, perceptual evaluations still have greater evidential value. One reason is that current measurement paradigms often result in a severe undersampling, undermining validity. All voice metrics exhibit considerable variation, not only across individuals, but also across the voice range. Making “voice maps” over fo × SPL reveals a surprising amount of variation, even in homogeneous populations of normophonic individuals; so normative averages are not to be found. However, under stringent protocol, individuals do systematically reproduce their own voice maps, as shown by Pabon and others. So, the norm could be the patient herself, if recorded prior to the pathology or the intervention. From comparing voice maps, not to a population norm, but to earlier takes of the same person, specific and detailed conclusions can be drawn., Invited keynote addressQC 20210608

Objectives: To determine if in singing there is an effect of lung volume on the electroglottographic waveform, and if so, how it varies over the voice range. Study design: Eight trained female singers sang the tune “Frère Jacques” in 18 conditions: three phonetic contexts, three dynamic levels, and high or low lung volume. Conditions were randomized and replicated. Methods: The audio and EGG signals were recorded in synchrony with signals tracking respiration and vertical larynx position. The first 10 Fourier descriptors of every EGG cycle were computed. These spectral data were clustered statistically, and the clusters were mapped by color into a voice range profile display, thus visualizing the EGG waveform changes under the influence of fo and SPL. The rank correlations and effect sizes of the relationships between relative lung volume and several adduction-related EGG wave shape metrics were similarly rendered on a color scale, in voice range profile-style ʻvoice maps.ʼ Results: In most subjects, EGG waveforms varied considerably over the voice range. Within subjects, reproducibility was high, not only across the replications, but also across the phonetic contexts. The EGG waveforms were quite individual, as was the nature of the EGG shape variation across the range. EGG metrics were significantly correlated to changes in lung volume, in parts of the range of the song, and in most subjects. However, the effect sizes of the relative lung volume were generally much smaller than the effects of fo and SPL, and the relationships always varied, even changing polarity from one part of the range to another. Conclusions: Most subjects exhibited small, reproducible effects of the relative lung volume on the EGG waveform. Some hypothesized influences of tracheal pull were seen, mostly at the lowest SPLs. The effects were however highly variable, both across the moderately wide fo-SPL range and across subjects. Different singers may be applying different techniques and comp, QC 20200703

Objectives: To determine if in singing there is an effect of lung volume on the electroglottographic waveform, and if so, how it varies over the voice range. Study design: Eight trained female singers sang the tune “Frère Jacques” in 18 conditions: three phonetic contexts, three dynamic levels, and high or low lung volume. Conditions were randomized and replicated. Methods: The audio and EGG signals were recorded in synchrony with signals tracking respiration and vertical larynx position. The first 10 Fourier descriptors of every EGG cycle were computed. These spectral data were clustered statistically, and the clusters were mapped by color into a voice range profile display, thus visualizing the EGG waveform changes under the influence of fo and SPL. The rank correlations and effect sizes of the relationships between relative lung volume and several adduction-related EGG wave shape metrics were similarly rendered on a color scale, in voice range profile-style ʻvoice maps.ʼ Results: In most subjects, EGG waveforms varied considerably over the voice range. Within subjects, reproducibility was high, not only across the replications, but also across the phonetic contexts. The EGG waveforms were quite individual, as was the nature of the EGG shape variation across the range. EGG metrics were significantly correlated to changes in lung volume, in parts of the range of the song, and in most subjects. However, the effect sizes of the relative lung volume were generally much smaller than the effects of fo and SPL, and the relationships always varied, even changing polarity from one part of the range to another. Conclusions: Most subjects exhibited small, reproducible effects of the relative lung volume on the EGG waveform. Some hypothesized influences of tracheal pull were seen, mostly at the lowest SPLs. The effects were however highly variable, both across the moderately wide fo-SPL range and across subjects. Different singers may be applying different techniques and comp, QC 20200703

Baseline data from adult speakers are presented for time-domain parameters of EGG waveforms. 26 vocally healthy adults (13 males and 13 females) were recruited for the study. Four dependent variables were computed: mean contact quotient, mean peak-rate-of change in the contact area, index of contacting, and the audio crest factor. Small regions around the speech range distribution modes on the fo/SPL plane were used to define means and gradients. Males and females differed considerably in the audio crest factor of their speaking voice, and somewhat in their EGG contact quotient when measured at the mode point of the individual speech range profile. In males, contacting tended to increase somewhat with fo and SPL around the mode point, while in females it tended to decrease., QC 20200204

Background: The flow ball is a device that creates a static backpressure in the vocal tract while providing real-time visual feedback of airflow. A ball height of 0 to 10 cm corresponds to airflows of 0.2 to 0.4. L/s. These high airflows with low transglottal pressure correspond to low flow resistances, similar to the ones obtained when phonating into straws with 3.7 mm diameter and of 2.8 cm length. Objectives: To investigate whether there are immediate effects of flow ball-assisted training on vocal fold contact. Methods: Ten singers (five males and five females) performed a messa di voce at different pitches over one octave in three different conditions: before, during and after phonating with a flow ball. For all conditions, both audio and electrolaryngographic (ELG) signals were simultaneously recorded using a Laryngograph microprocessor. The vocal fold contact quotient Qci (the area under the normalized EGG cycle) and dEGGmaxN (the normalized maximum rate of change of vocal fold contact area) were obtained for all EGG cycles, using the FonaDyn system. We introduce also a compound metric Ic ,the ‘index of contact’ [Qci × log10(dEGGmaxN)], with the properties that it goes to zero at no contact. It combines information from both Qci and dEGGmaxN and thus it is comparable across subjects. The intra-subject means of all three metrics were computed and visualized by colour-coding over the fo-SPL plane, in cells of 1 semitone × 1 dB. Results: Overall, the use of flow ball-assisted phonation had a small yet significant effect on overall vocal fold contact across the whole messa di voce exercise. Larger effects were evident locally, i.e., in parts of the voice range. Comparing the pre-post flow-ball conditions, there were differences in Qci and/or dEGGmaxN. These differences were generally larger in male than in female voices. Ic typically decreased after flow ball use, for males but not for females. Conclusion: Flow ball-assisted training seems to modify vocal fol, QC 20191112, Phonatory Dynamics and States

In a recent study we introduced a new approach for analysis of the electroglottographic (ECG) signal. This method is based on the evaluation of variation of the EGG signal and its first derivative, through new software developed by the Pisan phoniatric school. This software is designed to extract quantitative indices related to the contacting and decontacting phases of the vocal folds during phonation. The software allows us to study the combined variability of vibration amplitude and velocity (i.e. the first derivative of the EGG signal). Pathological voices show a much more variable EGG signal compared to normal voices, since cordal vibration is made irregular due to the presence of glottis plane pathologies. With the aim of demonstrating the differences between normal and pathological voices relevant to combined vibration amplitude and velocity variability, we have introduced a new quantitative parameter named "variability index, VI". We studied 95 subjects (35 normal and 60 with pathological voice); among pathologic subjects, 15 showed functional dysphonia and 45 showed organic dysphonia. Subjects affected by organic dysphonia presented: 15 bilateral vocal nodules, 15 unilateral polyps and 15 unilateral cysts. All subjects were studied with videolaryngostroboscopy; electro-acoustic parameters of the voice were analysed with the KayPENTAX CSL (Model 4500) system. The EGG signal was recorded using KAY Model 6103 connected to the CSL system. The new software for the analysis of the EGG signal allows us to obtain not only a VI total value relevant to variability during all the recording, but also partial VI values relevant to the different glottis cycle phases. In fact, plotting the amplitude variation and its first derivative on a Lissajous graph, it is possible to divide the whole glottis cycle into four phases (each represented by four quadrants on the graph): the initial vocal folds contacting activity (VI-Q1), the last phase of vocal folds contacting (VI-Q2), t

From soft to loud and low to high, the mechanisms of human voice have many degrees of freedom, making it difficult to assess phonation from the acoustic signal alone. FonaDyn is a research tool that combines acoustics with electroglottography (EGG). It characterizes and visualizes in real time the dynamics of EGG waveforms, using statistical clustering of the cycle-synchronous EGG Fourier components, and their sample entropy. The prevalence and stability of different EGG waveshapes are mapped as colored regions into a so-called voice range profile, without needing pre-defined thresholds or categories. With appropriately ‘trained’ clusters, FonaDyn can classify and map voice regimes. This is of potential scientific, clinical and pedagogical interest., This describes the FonaDyn software package, released into the public domain, and how to download it.QC 20180323

This master thesis describes early attempts at using electroglottography (EGG) to capture such changes in vocal fold vibration patterns that could be of interest to teachers of contemporary commercial music. After initial explorations, focus is placed on detecting potentially detrimental phonation; more specifically on the pressed quality often associated with loud singing in high register (belting). FonaDyn, a program written in the SuperCollider language, is used to detect pressedness using an algorithm based on K-means clustering of Fourier components of EGG cycles. Results indicate that pressedness affects phonation in ways detectable using EGG. Changes caused by pressedness seem to vary between registers and this variation is similar between subjects. Detection of pressedness in a subject is quite successful when training the algorithm on the same subject, but not always across subjects., Denna masteruppsats beskriver inledande försök att använda elektroglottografi (EGG) för att avläsa sådana förändringar i stämbandens vibrationsmönster som skulle kunna vara av intresse för sånglärare inom icke-klassisk stil. Tidiga undersökningar leder till att fortsatt fokus läggs på att detektera fonationstyper som kan orsaka röstskador; mer specifikt den typ av pressad röstkvalitet som ofta förknippas med stark sång i högt register (s.k. belting). FonaDyn, ett datorprogram skrivet i språket SuperCollider, används för att detektera pressad fonation med hjälp av K-means-klustring av EGG-cykler baserat på deras Fourierkomponenter. Resultaten indikerar att pressad fonation går att urskilja med hjälp av EGG. Kännetecknen för pressad fonation tycks skilja sig mellan röstregister och denna skillnad är snarlik hos olika försökspersoner. Programmet klarar av att känna igen pressad fonation hos samma person som algoritmen tränats på men inte alltid om algoritmen tränats på en annan sångare.

This thesis presents tools and components necessary to further develop an implementation of a method. The method attempts to use the non invasive electroglottographic signal to locate rapid transitions between voice registers. Implementations for sample entropy and the Discrete Fourier Transform (DFT) implemented for the programming language SuperCollider are presented along with tools necessary to evaluate the method and present the results in real time. Since different algorithms have been used, both for clustering and cycle separation, a comparison between algorithms for both of these steps has also been done., Denna rapport presenterar verktyg och komponenter som är nödvändiga för att vidareutveckla en implementation av en metod. Metoden försöker att använda en icke invasiv elektroglottografisk signal för att hitta snabba övergångar mellan röstregister. Det presenteras implementationer för sampelentropi och den diskreta fourier transformen för programspråket SuperCollider samt verktyg som behövs för att utvärdera metoden och presentera resultaten i realtid. Då olika algoritmer har använts för både klustring och cykelseparation så har även en jämförelse mellan algoritmer för dessa steg gjorts.

This master thesis describes early attempts at using electroglottography (EGG) to capture such changes in vocal fold vibration patterns that could be of interest to teachers of contemporary commercial music. After initial explorations, focus is placed on detecting potentially detrimental phonation; more specifically on the pressed quality often associated with loud singing in high register (belting). FonaDyn, a program written in the SuperCollider language, is used to detect pressedness using an algorithm based on K-means clustering of Fourier components of EGG cycles. Results indicate that pressedness affects phonation in ways detectable using EGG. Changes caused by pressedness seem to vary between registers and this variation is similar between subjects. Detection of pressedness in a subject is quite successful when training the algorithm on the same subject, but not always across subjects., Denna masteruppsats beskriver inledande försök att använda elektroglottografi (EGG) för att avläsa sådana förändringar i stämbandens vibrationsmönster som skulle kunna vara av intresse för sånglärare inom icke-klassisk stil. Tidiga undersökningar leder till att fortsatt fokus läggs på att detektera fonationstyper som kan orsaka röstskador; mer specifikt den typ av pressad röstkvalitet som ofta förknippas med stark sång i högt register (s.k. belting). FonaDyn, ett datorprogram skrivet i språket SuperCollider, används för att detektera pressad fonation med hjälp av K-means-klustring av EGG-cykler baserat på deras Fourierkomponenter. Resultaten indikerar att pressad fonation går att urskilja med hjälp av EGG. Kännetecknen för pressad fonation tycks skilja sig mellan röstregister och denna skillnad är snarlik hos olika försökspersoner. Programmet klarar av att känna igen pressad fonation hos samma person som algoritmen tränats på men inte alltid om algoritmen tränats på en annan sångare.

This thesis presents tools and components necessary to further develop an implementation of a method. The method attempts to use the non invasive electroglottographic signal to locate rapid transitions between voice registers. Implementations for sample entropy and the Discrete Fourier Transform (DFT) implemented for the programming language SuperCollider are presented along with tools necessary to evaluate the method and present the results in real time. Since different algorithms have been used, both for clustering and cycle separation, a comparison between algorithms for both of these steps has also been done., Denna rapport presenterar verktyg och komponenter som är nödvändiga för att vidareutveckla en implementation av en metod. Metoden försöker att använda en icke invasiv elektroglottografisk signal för att hitta snabba övergångar mellan röstregister. Det presenteras implementationer för sampelentropi och den diskreta fourier transformen för programspråket SuperCollider samt verktyg som behövs för att utvärdera metoden och presentera resultaten i realtid. Då olika algoritmer har använts för både klustring och cykelseparation så har även en jämförelse mellan algoritmer för dessa steg gjorts.

Phonation into glass tubes (resonance tubes), keeping the free end of the tube in water, has been a frequently used voice therapy method in Finland and more recently also in other countries. The purpose of this exploratory study was to investigate what effects tube phonation with and without water has on the larynx. Two participants were included in the study. The methods used were high-speed imaging, electroglottographic observations of vocal fold vibrations, and measurements of oral pressure during tube phonation. Results showed that the fluctuation in the back pressure during tube phonation in water altered the vocal fold vibrations. In the high-speed imaging, effects were found in the open quotient and amplitude variation of the glottal opening. The open quotient increased with increasing water depth (from 2 cm to 6 cm). A modulation effect by the water bubbles on the vocal fold vibrations was seen both in the high-speed glottal area tracings and in the electroglottography signal. A second experiment revealed that the increased average oral pressure was largely determined by the water depth. The increased open quotient can possibly be explained by an increased abduction of the vocal folds and/or a reduced transglottal pressure. The back pressure of the bubbles also modulates glottal vibrations with a possible massage effect on the vocal folds. This effect and the well-defined average pressure increase due to the known water depth are different from those of other methods using a semi-occluded vocal tract., QC 20160208. QC 20160318

The vocal folds can oscillate in several different ways, manifest to practitioners and clinicians as ‘registers’ or ‘mechanisms’, of which the two most commonly considered are modal voice and falsetto voice. Here these will be taken as instances of different ‘vibratory states’, i.e., distinct quasi-stationary patterns of vibration of the vocal folds. State transitions are common in biomechanical nonlinear oscillators; and they are often abrupt and impossible to predict exactly. Switching state is much like switching to a different voice. Therefore, vibratory states are a source of confounding variation, for instance, when acquiring a voice range profile (VRP). In the quest for a state-aware, non-invasive VRP, a semi-automatic method based on the short-term spectrum of the electroglottographic signal (EGG) was developed. The method identifies rapid vibratory state transitions, such as the modal-falsetto switch, and clusters the EGG data based on their similarities in the relative levels and phases of the lower frequency components. Productions of known modal and falsetto voice were accurately clustered by a Gaussian mixture model. When mapped into the VRP, this EGG-based clustering revealed connected regions of different vibratory sub-regimes in both modal and falsetto., Updated from submitted to published.QC 20140815, FonaDyn

The human voice is a product of an intricate biophysical system. The complexity of this system enables a rich variety of possible sounds, but at the same time poses great challenges for quantitative voice analysis. For example, the vocal folds can vibrate in several different ways, leading to variations in the acoustic output. Because the vocal folds are relatively inaccessible, such variations are often difficult to account for. This work proposes a novel method for extracting non-invasively information on the vibratory state of the human vocal folds. Such information is important for creating a more complete voice analysis scheme. Invasive methods are undesirable because they often disturb the subjects and/or the studied phenomena, and they are also impractical in terms of accessibility and cost. A useful frame of reference for voice analysis is the Voice Range Profile (VRP). The 3 dimensional form of the VRP can be used to depict any phonatory metric over the 2 dimensional plane defined by the fundamental frequency of phonation (x-axis) and the sound pressure level (y-axis). The primary goal of this work was to incorporate information on the vibratory state of the vocal folds into the Voice Range Profile (e.g., as a color change). For this purpose, a novel method of analysis of the electroglottogram (EGG) was developed, using techniques from machine learning (clustering) and nonlinear time series analysis (sample entropy estimation). The analysis makes no prior assumptions on the nature of the EGG signal and does not rely on its absolute amplitude or frequency. Unlike time-domain methods, which typically define thresholds for quantifying EGG cycle metrics, the proposed method uses information from the entire cycle of each period. The analysis was applied in a variety of experimental conditions (constant vowel with different vibratory states, constant vibratory state and different vowels, constant vowel and vibratory state with varying lung volume) and the magnitu, QC 20140609, FonaDyn

The human voice is a product of an intricate biophysical system. The complexity of this system enables a rich variety of possible sounds, but at the same time poses great challenges for quantitative voice analysis. For example, the vocal folds can vibrate in several different ways, leading to variations in the acoustic output. Because the vocal folds are relatively inaccessible, such variations are often difficult to account for. This work proposes a novel method for extracting non-invasively information on the vibratory state of the human vocal folds. Such information is important for creating a more complete voice analysis scheme. Invasive methods are undesirable because they often disturb the subjects and/or the studied phenomena, and they are also impractical in terms of accessibility and cost. A useful frame of reference for voice analysis is the Voice Range Profile (VRP). The 3 dimensional form of the VRP can be used to depict any phonatory metric over the 2 dimensional plane defined by the fundamental frequency of phonation (x-axis) and the sound pressure level (y-axis). The primary goal of this work was to incorporate information on the vibratory state of the vocal folds into the Voice Range Profile (e.g., as a color change). For this purpose, a novel method of analysis of the electroglottogram (EGG) was developed, using techniques from machine learning (clustering) and nonlinear time series analysis (sample entropy estimation). The analysis makes no prior assumptions on the nature of the EGG signal and does not rely on its absolute amplitude or frequency. Unlike time-domain methods, which typically define thresholds for quantifying EGG cycle metrics, the proposed method uses information from the entire cycle of each period. The analysis was applied in a variety of experimental conditions (constant vowel with different vibratory states, constant vibratory state and different vowels, constant vowel and vibratory state with varying lung volume) and the magnitu, QC 20140609, FonaDyn

The human voice is a product of an intricate biophysical system. The complexity of this system enables a rich variety of possible sounds, but at the same time poses great challenges for quantitative voice analysis. For example, the vocal folds can vibrate in several different ways, leading to variations in the acoustic output. Because the vocal folds are relatively inaccessible, such variations are often difficult to account for. This work proposes a novel method for extracting non-invasively information on the vibratory state of the human vocal folds. Such information is important for creating a more complete voice analysis scheme. Invasive methods are undesirable because they often disturb the subjects and/or the studied phenomena, and they are also impractical in terms of accessibility and cost. A useful frame of reference for voice analysis is the Voice Range Profile (VRP). The 3 dimensional form of the VRP can be used to depict any phonatory metric over the 2 dimensional plane defined by the fundamental frequency of phonation (x-axis) and the sound pressure level (y-axis). The primary goal of this work was to incorporate information on the vibratory state of the vocal folds into the Voice Range Profile (e.g., as a color change). For this purpose, a novel method of analysis of the electroglottogram (EGG) was developed, using techniques from machine learning (clustering) and nonlinear time series analysis (sample entropy estimation). The analysis makes no prior assumptions on the nature of the EGG signal and does not rely on its absolute amplitude or frequency. Unlike time-domain methods, which typically define thresholds for quantifying EGG cycle metrics, the proposed method uses information from the entire cycle of each period. The analysis was applied in a variety of experimental conditions (constant vowel with different vibratory states, constant vibratory state and different vowels, constant vowel and vibratory state with varying lung volume) and the magnitu, QC 20140609, FonaDyn

The human voice is a product of an intricate biophysical system. The complexity of this system enables a rich variety of possible sounds, but at the same time poses great challenges for quantitative voice analysis. For example, the vocal folds can vibrate in several different ways, leading to variations in the acoustic output. Because the vocal folds are relatively inaccessible, such variations are often difficult to account for. This work proposes a novel method for extracting non-invasively information on the vibratory state of the human vocal folds. Such information is important for creating a more complete voice analysis scheme. Invasive methods are undesirable because they often disturb the subjects and/or the studied phenomena, and they are also impractical in terms of accessibility and cost. A useful frame of reference for voice analysis is the Voice Range Profile (VRP). The 3 dimensional form of the VRP can be used to depict any phonatory metric over the 2 dimensional plane defined by the fundamental frequency of phonation (x-axis) and the sound pressure level (y-axis). The primary goal of this work was to incorporate information on the vibratory state of the vocal folds into the Voice Range Profile (e.g., as a color change). For this purpose, a novel method of analysis of the electroglottogram (EGG) was developed, using techniques from machine learning (clustering) and nonlinear time series analysis (sample entropy estimation). The analysis makes no prior assumptions on the nature of the EGG signal and does not rely on its absolute amplitude or frequency. Unlike time-domain methods, which typically define thresholds for quantifying EGG cycle metrics, the proposed method uses information from the entire cycle of each period. The analysis was applied in a variety of experimental conditions (constant vowel with different vibratory states, constant vibratory state and different vowels, constant vowel and vibratory state with varying lung volume) and the magnitu, QC 20140609, FonaDyn

The human voice is a product of an intricate biophysical system. The complexity of this system enables a rich variety of possible sounds, but at the same time poses great challenges for quantitative voice analysis. For example, the vocal folds can vibrate in several different ways, leading to variations in the acoustic output. Because the vocal folds are relatively inaccessible, such variations are often difficult to account for. This work proposes a novel method for extracting non-invasively information on the vibratory state of the human vocal folds. Such information is important for creating a more complete voice analysis scheme. Invasive methods are undesirable because they often disturb the subjects and/or the studied phenomena, and they are also impractical in terms of accessibility and cost. A useful frame of reference for voice analysis is the Voice Range Profile (VRP). The 3 dimensional form of the VRP can be used to depict any phonatory metric over the 2 dimensional plane defined by the fundamental frequency of phonation (x-axis) and the sound pressure level (y-axis). The primary goal of this work was to incorporate information on the vibratory state of the vocal folds into the Voice Range Profile (e.g., as a color change). For this purpose, a novel method of analysis of the electroglottogram (EGG) was developed, using techniques from machine learning (clustering) and nonlinear time series analysis (sample entropy estimation). The analysis makes no prior assumptions on the nature of the EGG signal and does not rely on its absolute amplitude or frequency. Unlike time-domain methods, which typically define thresholds for quantifying EGG cycle metrics, the proposed method uses information from the entire cycle of each period. The analysis was applied in a variety of experimental conditions (constant vowel with different vibratory states, constant vibratory state and different vowels, constant vowel and vibratory state with varying lung volume) and the magnitu, QC 20140609, FonaDyn

The human voice is a product of an intricate biophysical system. The complexity of this system enables a rich variety of possible sounds, but at the same time poses great challenges for quantitative voice analysis. For example, the vocal folds can vibrate in several different ways, leading to variations in the acoustic output. Because the vocal folds are relatively inaccessible, such variations are often difficult to account for. This work proposes a novel method for extracting non-invasively information on the vibratory state of the human vocal folds. Such information is important for creating a more complete voice analysis scheme. Invasive methods are undesirable because they often disturb the subjects and/or the studied phenomena, and they are also impractical in terms of accessibility and cost. A useful frame of reference for voice analysis is the Voice Range Profile (VRP). The 3 dimensional form of the VRP can be used to depict any phonatory metric over the 2 dimensional plane defined by the fundamental frequency of phonation (x-axis) and the sound pressure level (y-axis). The primary goal of this work was to incorporate information on the vibratory state of the vocal folds into the Voice Range Profile (e.g., as a color change). For this purpose, a novel method of analysis of the electroglottogram (EGG) was developed, using techniques from machine learning (clustering) and nonlinear time series analysis (sample entropy estimation). The analysis makes no prior assumptions on the nature of the EGG signal and does not rely on its absolute amplitude or frequency. Unlike time-domain methods, which typically define thresholds for quantifying EGG cycle metrics, the proposed method uses information from the entire cycle of each period. The analysis was applied in a variety of experimental conditions (constant vowel with different vibratory states, constant vibratory state and different vowels, constant vowel and vibratory state with varying lung volume) and the magnitu, QC 20140609, FonaDyn

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 80 dB at 0.3 m 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., QC 20131011

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 80 dB at 0.3 m 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.

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 80 dB at 0.3 m 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.

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 80 dB at 0.3 m 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.

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 80 dB at 0.3 m 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.

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 80 dB at 0.3 m 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.

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 80 dB at 0.3 m 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.

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 ID 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., QC 20110204

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., QC 20100923

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.

Sustained phonations were compared in two groups of children (aged 7-12), one with special artistic voice education and one from a normal school, without voice complaints or problems. The hypothesis of specific (better) biomechanical vocal fold properties in the first group is confronted with the hypothesis of differences solely related to training of voice control. In both groups, Fo-aperiodicity was measured in a sustained phonation at 3 different SPL levels. As a general rule, aperiodicity clearly decreases when the voice becomes louder. Aperiodicity is highly significantly lower, at all SPL-levels, in children with trained singing voices: this implies better mechanical properties of the vocal oscillator. The Fo/SPL relation on a sustained /a:/ does not differ in trained and untrained children's voices: out of singing context, trained children do not spontaneously control the Fo/SPL dynamics differently from untrained children. The higher regularity of vocal fold pulsed is not related to the duration of training.