Electroglottographic Measures Research Articles

Effects on Voice Quality of Thyroidectomy: A Qualitative and Quantitative Study Using Voice Maps

ObjectivesThis 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. MethodsA voice-mapping analysis paradigm was applied retrospectively on a corpus of spoken and sung sentences produced by patients who had had thyroid surgery. Voice quality changes were assessed objectively for 57 patients prior to surgery and two months after surgery, by making comparative voice maps, pre- and post-intervention, of six acoustic and electroglottographic (EGG) metrics. ResultsAfter 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.

Multiparametric Analysis of Dysphonic Voice - An Evidence from the Discriminant Analysis.

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.

Medidas de efeito das intervenções em vozes saudáveis: uma revisão de escopo

ABSTRACT Purpose to map the vocal assessment measures used to verify the effect of the intervention in vocally healthy individuals. Research strategy This is a scope review based on the research question: What vocal assessment measures are used to verify the effect of the intervention in vocally healthy individuals? The search was carried out electronically in MEDLINE (PubMed), LILACS (BVS), Scopus (Elsevier), Web of Science (Clarivate), Embase and Cochrane databases. Selection criteria The selection of studies was based on reading the titles, abstracts, keywords and full texts, applying the eligibility criteria. Data related to the publication’s bibliographic information, sample and intervention characteristics, the effects of the intervention on self-assessment, auditory-perceptual, acoustic, aerodynamic, electroglottographic measures, laryngeal examination results, among others, were extracted. The data were summarized and presented in a quantitative and descriptive way. Results 97 articles were selected, among the 979 studies mapped in this review. Acoustic analysis was the most used measure (n=70, 72.3%) to verify the effects of vocal training in the selected studies, followed by electroglottography (n= 55, 56.7%), self-assessment (n= 38, 39 .2%), aerodynamics (n= 33, 34.0%), auditory-perceptual judgment (n= 22, 22.7%) and laryngeal examination (n= 16, 16.5%). Conclusion Acoustic analysis is the measure used in most studies to verify the effect of the intervention in vocally healthy individuals.

Valores de referência para dados eletroglotográficos de idosas

ABSTRACT Purpose To present reference values for fundamental frequency data and closed-phase quotient extracted from electroglottography in older women and verify if they differ from laryngeal examination results. Methods Observational analytical cross-sectional study in 73 older women, aged 60 to 84 years, using electroglottographic and laryngeal examinations. Each participant’s voice sample had a sustained prolonged vowel /a/ emitted at the usual frequency and intensity, in the modal register. Fundamental frequency (F0) and vocal fold contact quotient (CQ) were extracted from the electroglottography. Data were descriptively analyzed with measures of central tendency and dispersion of continuous variables. To establish whether continuous electroglottography variables differed from the laryngeal diagnosis, Student’s t-test (parametric test) and Mann-Whitney (non-parametric test) were performed. The significance level in all tests was set at 5%. Results Most participants did not have laryngeal changes, while 27.4% had presbylarynx. The mean electroglottographic measures were 187.24 Hz for F0 and 48.49% for CQ. There was no statistical significance between laryngeal examinations and EGG measures. Conclusion Older women have mean electroglottographic F0 values of 187.24 Hz and CQ of 48.49%. Electroglottographic F0 and CQ measures did not change with the presence of the presbylarynx in older women.

Receiver operating characteristic analysis of acoustic and electroglottographic parameters with different sustained vowels

Objective To examine the power of the parameters obtained from different sustained vowels used in acoustic and electroglottographic (EGG) voice evaluation protocols to discriminate between dysphonic and non-dysphonic voice quality. Methods Sixty non-dysphonic participants and 30 dysphonic participants were included in the study. In addition to the time domain amplitude and frequency perturbation parameters obtained from the sustained phonation of /ʌ/-/ɛ/-/i/-/u/ vowels, several frequency-domain spectral/cepstral parameters and EGG parameters were evaluated. The classification performance of the acoustic and electroglottographic measures was quantified using analysis and receiver operating characteristic (ROC) curve analysis. Results As a result of ROC analysis, the discriminative diagnostic performance (area under the curve, AUC) of the test for low-vowel (/ʌ/-/ɛ/) phonation was higher than values obtained from high-vowel (/i/-/u/) phonation. For /ʌ/ and /ɛ/ sustained vowels, the parameters exhibiting the highest discrimination were fundamental frequency standard deviation (fo/STD), cepstral peak prominence (CPP), relative average perturbation (RAP), pitch perturbation quotient (PPQ), and jitter percent (JITT). In the EGG parameters, on the other hand, average jitter and periodicity parameters obtained from front vowels (/ɛ/-/i/) were found to have higher AUC values compared to back vowels (/ʌ/-/u/). Conclusions In acoustic analyses, /ʌ/ and /ɛ/ sustained vowels give the highest diagnostic performance. In the electroglottographic evaluation, on the other hand, /ɛ/ and /i/ vowels, when the position of the tongue is forward, have better classification performance compared to /ʌ/ and /u/ vowels, when the position of the tongue is back.

Which Sung Pitch Range is Best for Boys During Voice Change?

The question of how and what boys should sing during adolescent voice change has challenged educators and choir leaders for the last century. As the larynx enlarges during adolescence, most boys will follow the descending pitch of their speaking voice and move to singing vocal parts with a lower pitch range. Occasionally a boy may continue to sing in his treble (soprano) range while his larynx is growing and his speaking pitch is lowering. There is much opinion on the wisdom of such practices, but until now there has been no quantifiable evidence to illustrate the discussion. The established historic and cultural practices can now be reassessed in the light of quantitative analyses of vocal function. This longitudinal case study used electroglottographic measures from one boy over a 3-year period to investigate the efficiency of vocal fold adductory behavior in both prechange and midchange singing. In the first recording, he is aged 10 years old and has an unchanged voice. In the second recording, he is aged 13 years old and has a speaking voice in the Cooksey Stage III of voice change. Up to and including the time of the second recording, he had chosen to remain singing exclusively in his treble (soprano) range. The comparison between the two recordings of the observed regularity and efficiency of vocal fold adduction suggests that singing in this pitch range has become less healthy and effective; this is also represented in the overall perceived vocal comfort levels heard in the recordings. The implications for educators are that the longitudinal development of singing habits will be enhanced for boys who move to singing with their new baritone range as their larynx grows, rather than remaining in a treble range.

The effects of age and pitch level on electroglottographic measures during sustained phonation.

The aim of the present study was to use electroglottography (EGG) to explore the effects of age and pitch level on sustained vowel phonation. Thirty female individuals (10 young, 10 middle-aged, and 10 older speakers) without voice disorders or training in singing participated in this study. Eight EGG parameters were measured during sustained vowel production with a high, mid, or low pitch: fundamental frequency, contact quotient, contacting-time quotient, decontacting-time quotient, speed quotient with a midslope criterion (SQ-mid), jitter, shimmer, and the harmonics-to-noise ratio. Age was found to be a significant factor in fundamental frequency, contact quotient, contacting-time quotient, decontacting-time quotient, and SQ-mid. With increasing age, the mean fundamental frequency decreased while the contact quotient increased. The middle-aged and older speakers had more asymmetrical vocal fold vibratory patterns than the young speakers. As for pitch level, the high pitch had a significantly less decontacting-time quotient and greater SQ-mid than low and mid pitches. The lack of significant interaction between age and pitch level indicates that the effects of age and pitch level could be additive. Finally, the discriminant analyses show that contact quotient is an important factor in predicting the age of a voice.

Respiratory and electroglottographic measures of normal and loud speech across vowels

Respiratory and electroglottographic measures of normal and loud speech across vowels

응용 입술 트릴 훈련이 뮤지컬 전공 학생의 음성 변화에 미치는 효과

The Modified Voiced Lip Trill (MVoLT) training is a variant of voiced lip-till training characterized by increased loudness, lowered laryngeal position, and lip contact facilitated with fingers. The purpose of the current study was to assess the effect of the MVoLT training program on vocal changes of musical singing theater students. A total of 32 musical theater students (17 males and 15 females, age ranging from 18 to 29) participated in the study. For about three months, each participant was tutored using a systematic program focussing on the MVoLT training, accompanied by certain facilitating strategies. Pre- & post-training multi-dimensional vocal characteristics were assesed and compared. Results showed that cepstral peak prominence during vowel phonation increased after training, while its standard deviation and Cepstral Spectral Index of Dysphonia decreased. When an aerodynamic assessment was performed, maximum phonation time, subglottal pressure, mean airflow rate increased, while electroglottographic measures did not change. In addition, decreased psychometric measures, higher maximum pitch, and increased vocal range were noted after training. In conclusion, the MVoLT was proven to have a potential as an effective and safe training method for musical theater singing.

An Acoustic and Electroglottographic Study of the Aging Voice With and Without an Open Jaw Posture

This study aimed to determine if the use of an "open jaw" posture in healthy aging adults would result in voice improvement detectable through acoustic and electroglottographic measurements. A convenience sampling strategy was used to recruit 85 participants, with at least five females and five males in each of four age groups, between age 35 and 50years (35+), above 50(50+), 60+, and 70+ years. Participants sustained the vowel /a/ at three pitch levels (normal, low, and high) and repeated the test sentence "We saw two cars" in both a normal and an open jaw postures. A selection of acoustic and electroglottographic measures were derived from the steady midportion of the vowel segments extracted from the sustained and embedded vowels to identify measures sensitive to the effects of jaw posture, age group, gender, and pitch. Results from a four-way (two jaw postures × four age groups × two genders × three pitch levels) Mixed Model Multivariate Analysis of Variance showed a significant four-way interaction effect. For both genders, an open jaw posture led to an increase of fundamental frequency (F0), formant one frequency, and vowel space area and a decrease of the amplitude difference of the first two harmonics and %Jitter. With an open jaw posture, speed quotient decreased for females and open quotient increased for females but decreased for males. An open jaw posture was generally associated with positive changes in vocal behaviors, including higher F0, improved phonatory stability, and voice clarity.

Semi-Occluded Vocal Tract Exercises: Aerodynamic and Electroglottographic Measurements in Singers

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

Phonation in nine languages

This study compares the phonations of 9 languages. Some of the languages use phonation types contrastively, independently of any pitch contrasts (Gujarati: modal, breathy; White Hmong and Black Miao: modal, breathy; Jalapa Mazatec: modal, breathy, creaky; Southern Yi, Bo, and Hani: tense, lax), while some use phonation as correlates of pitch contrasts (White Hmong: creaky low tone; Black Miao: creaky low tone and pressed high tone; Mandarin: creaky low and falling tones; Santiago Matatlán Zapotec and San Juan Guelavia Zapotec: creaky large-falling tone and breathy small-falling tone). Acoustic measures of phonation are compared for all 9 languages, and electroglottographic measures are compared for all but Mazatec. Multi-dimensional scaling of the production measures is then used to derive a lower-dimension phonation space, and the use of that production space by the different languages is compared. [Work supported by NSF]

An acoustic and electroglottographic study of White Hmong tone and phonation

This study examines tone and phonation in White Hmong, a language with seven tones (traditionally described as: high, mid, low, high-falling, mid-rising, low-falling, and mid-low) and three phonations (low-falling tone is creaky, mid-low tone is breathy and the remaining tones are modal). Thirty-two speakers were recorded producing words with all seven tones; audio and electroglottographic recordings were made. Acoustic measures were: cepstral peak prominence (CPP), H1⁎, H2⁎, H1⁎−H2⁎, H1⁎−A1⁎, H1⁎−A2⁎, H1⁎−A3⁎, and H2⁎−H4⁎. Electroglottographic (EGG) measures were: closed quotient and derivative-EGG closure peak amplitude (DECPA). F0 and duration were measured. Results showed that the traditional tonal descriptions are accurate except for the high-level tone which is better described as rising and the mid-low tone, which is falling. Furthermore, the rising and low-falling tones are shorter than the other five tones. In terms of acoustic and electroglottographic measures, none of the measures tested distinguished all three phonation types at a given time point. Several measures, H1⁎, H1⁎−H2⁎, CQ, CPP, and DECPA, distinguished two phonation categories, suggesting that phonation contrasts are realized across several phonetic dimensions. Additional results showed that many of the acoustic and EGG measures were correlated with F0 and that closed quotient and DECPA were most strongly correlated with H1⁎−H2⁎.

The effects of cigarette smoking on the female voice

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

Breathy phonation in Gujarati: An acoustic and electroglottographic study.

Recent electroglottographic research on Gujarati [Khan (2009)] reveals that speakers consistently distinguish breathy and modal vowels (e.g., /bar/ “twelve” vs /bAr/ “outside;” capitalization represents breathiness) by both closed quotient and closing velocity. Despite this interspeaker uniformity measured at the voice source, the acoustic correlates of the contrast measured in the speech output vary considerably across speakers. While some speakers mark breathiness with a larger H1-H2 difference, others use lower periodicity (CPP) or greater changes in intensity (rms energy). It is unclear how breathy vowels are contrasted with modal vowels following breathy consonants (e.g., /bAr/ “outside” vs /Bar/ “burden”) or to what extent the preceding consonant manner can affect the spectral acoustics of the vowel (e.g., /pAr/ “mountain” vs /vAn/ “vehicle”). To better capture the variation in both vowel and consonant phonations, the current study examines acoustic and electroglottographic data collected from naturalistic productions of near-minimal sets from a larger pool of Gujarati speakers, using a wider range of vowel and consonant types. Preliminary results suggest that while all speakers distinguish phonation types in both consonants and vowels based on electroglottographic measures, the acoustic cues in the output are far more complex. [Work supported by NSF.]

Acoustic and Electroglottographic Voice Characteristics in Chronic Cough and Paradoxical Vocal Fold Movement

Objective: Chronic cough (CC) and paradoxical vocal fold movement (PVFM) may be associated with voice problems. Objective acoustic and electroglottographic (EGG) measures have the capacity to delineate these vocal characteristics. This study investigated acoustic and EGG voice features of CC and PVFM. Patients and Methods: Acoustic and EGG findings were compared among 5 groups of participants. The first 3 groups, CC (n = 56), PVFM (n = 8) and combined CC-PVFM (n = 55), included individuals with cough and respiratory symptoms that persisted despite medical treatment. Groups 4 and 5 included individuals with muscle tension dysphonia (n = 25) and healthy controls (n = 27). Results: Participants with CC/PVFM recorded reduced phonation times (p < 0.001), greater jitter (p < 0.001), reduced harmonic to noise ratio (p = 0.001), reduced phonation range (p = 0.007) and shorter closed phase of vocal fold vibration (p = 0.006) in comparison to healthy controls. Females with CC had reduced fundamental frequency in connected speech (p = 0.009). There was consistent overlap between the participants with CC and those with PVFM. Duration of closed phase and fundamental frequency were lower in the participants with CC and PVFM than in those with muscle tension dysphonia. Conclusion: These results confirm abnormalities in acoustic and EGG voice features in CC and PVFM.

Electroglottographic Measures Based on GCI and GOI Detection Using Multiscale Product

This paper deals with glottal parameter estimation such as local pitch and open quotient from electroglottographic signal (EGG). This estimation is based on glottal closing instants and glottal opening instants determined by a multi-scale product of this signal. Wavelet transform of EGG signal is made with a quadratic spline function. Wavelet coefficients calculated on different dyadic scales, show modulus maxima at localized discontinuities of EGG signal. The detected maxima and minima correspond to the glottal opening and closing instants called GOIs and GCIs. To improve the estimate precision, we operate the multi-scale product of wavelet transform coefficients of three successive dyadic scales. This processing enhances edge detection. A Multi-scale product is a nonlinear combination of successive scales; it reduces noise and spurious peaks. We apply cubic root amplitude on the product to improve the representation of weak amplitudes. The method has a good representation of GCI and a best detection of GOI. The method was tested on the Keele University database; it is effective and robust in multiple cases even for a typical signal showing undetermined GOIs and multiple peaks at GCIs. Finally precise measurement of these instants allows accurate estimation of prosodic parameters as local pitch and open quotient.

Electroglottographic measurements of glottal function in vocal fold paralysis in women

The purpose of the study was to determine how electroglottographic measures change with voice recovery in women with vocal fold palsy compared with healthy speakers, and which coefficient best represents dysphonia. An electroglottograph with speech studio 1.04 software was used to record and analyse the data. Electroglottographic data were collected from 22 female patients and 16 healthy female speakers. Our findings show that the mean values of open quotient (OpQ), closing quotient (ClQ), % Irregularity and contact quotient (Qx) differ between the groups of patients and controls. % Irregularity, Qx and OpQ significantly correlated with the perceptual degree of dysphonia. Electroglottographic recordings can objectify dysphonia in patients with vocal fold palsy. Electroglottography is a suitable non-invasive tool for tracking the patients' long-term progress. % Irregularity best represents the vocal fold dysfunction in patients with a vocal fold palsy.

Electroglottographic tracking of phonatory response to Botox.

Botox injection into the thyroarytenoid muscle is thought to alter the glottal competence and laryngeal adduction of patients with adductor spasmodic dysphonia (ADSD). Hypofunctional responses to treatment have been rated subjectively and inferred from postinjection breathy voice, aphonia, midline glottal gap, or subclinical aspiration. Clinical experience suggests that temporary hypofunction varies in duration and severity among patients. This study used electroglottographic measures to examine changes over time in glottal competence during the relatively stable phonation produced by 5 patients with ADSD. Hierarchical linear modeling was used to test 3 hypotheses: (a) that reduced laryngeal adduction would occur during the first 3 weeks postinjection, followed by a reversal; (b) that patients' hypofunctional response curves would differ one from another; and (c) that changes in adduction, if present, would be related to changes in severity ratings of ADSD symptoms. For 3 participants, significant hypoadduction occurred after injection and reversed toward preinjection level over an 8-week period. Two participants demonstrated a flat or increasing vocal fold contact response curve during the early postinjection period. Observations were consistent with the previously reported differences and possibly complex relation between the resolution of breathy hypofunction and ultimate return of ADSD symptoms.

Comparison of Aerodynamic and Electroglottographic Parameters in Evaluating Clinically Relevant Voicing Patterns

The purpose of the present study was to identify one or more aerodynamic or electroglottographic measures that distinguish among voicing patterns that are clinically relevant for nodule pathogenesis and regression: a presumably pathogenic pattern (pressed voice), a neutral pattern (normal voice), and two presumably therapeutic patterns (resonant voice and breathy voice). Trained subjects with normal voices produced several tokens of each voice type on sustained vowels /a/, /i/, and /u/. For each token, maximum flow declination rate, alternating current flow, and minimum flow were obtained from inverse-filtered airflow signals, and closed quotient and closing time were obtained from electroglottographic signals. The results indicate that for /a/ and /i/ (but not for /u/), the closed quotient provides a sensitive tool for distinguishing the voice types in physiologically interpretable directions. Further, post-hoc analyses confirmed a direct relationship between the closed quotient and videoscopic ratings of laryngeal adduction, which previous work links to nodule pathogenesis and regression.