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ABSTRACT: Human voice production at very high fundamental frequencies is not yet understood in detail. It was hypothesized that these frequencies are produced by turbulences, vocal tract/vocal fold interactions, or vocal fold oscillations without closure. Hitherto it has been impossible to visually analyze the vocal mechanism due to technical limitations. Latest high-speed technology, which captures 20 000 frames/s, using transnasal endoscopy was applied. Up to 1568 Hz human vocal folds do exhibit oscillations with complete closure. Therefore, the recent results suggest that human voice production at very high F0s up to 1568 Hz is not caused by turbulence, but rather by airflow modulation from vocal fold oscillations.
The Journal of the Acoustical Society of America 02/2013; 133(2):EL82-EL87. · 1.55 Impact Factor
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ABSTRACT: INTRODUCTION: Previous studies using dynamic real-time magnetic resonance imaging (MRI) to analyze vocal tract configurations in singers are limited by the fact that the image acquisitions were performed in the supine position. The aim of this study was to examine differences of the vocal tract shape in professional tenors between supine and upright positions. MATERIAL AND METHODS: The vocal tract profiles of nine professional Western classically trained tenors were analyzed using a rotating MRI scanner (0.25T). The singers performed sustained tones in an ascending scale from C4 (262Hz) to A4 (440Hz) on the vowel /a/ in supine and upright positions, starting in modal register and continuing to their stage voice above passaggio or changing to falsetto register, respectively. RESULTS: Many articulators such as lip opening, jaw opening, tongue position, and uvula position were not affected by the subjects' positions. However, the larynx was found to be higher (P<0.001) and the jaw more protruded (P<0.001) for the supine position. The general changes associated with pitch and register were not affected by these systematic differences. CONCLUSIONS: The effect of supine versus upright position on the vocal tract shape is considered to be rather small in professional tenors. The modifications in the vocal tract associated with register and pitch are not affected to a great extent by the position.
Journal of voice: official journal of the Voice Foundation 02/2013; · 0.95 Impact Factor
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ABSTRACT: PURPOSE OF REVIEW: For a number of years, it has been possible to use dynamic real-time magnetic resonance imaging (MRI) to analyse the dynamic processes which occur in the human body. In the fields of laryngology and phoniatrics, such dynamic processes are found not only in swallowing, but also in voice and speech production. This article aims to present an overview of how the use of MRI might add to our current understanding of the dynamic processes involved in voice production. RECENT FINDINGS: It is shown that up to now the analysis of vocal fold oscillations has been limited by MRI's relatively low sampling rate of up to 50 Hz. Nevertheless, more detailed analysis does seem possible with regard to the modulation of the power source and vocal tract. SUMMARY: Dynamic real-time MRI offers a great opportunity for the analysis of voice production in all stages of the voice production system.
Current opinion in otolaryngology & head and neck surgery 10/2012;
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ABSTRACT: Vocal register transitions in the passaggio region remain an unclarified field in classically trained male singers.
We examined the acoustic and electroglottographic signals of seven tenors' transitions from voix mixte to falsetto on a sustained pitch F4 (349Hz) on the vowels /a, e, i, o, u, and æ/.
It was found that in many of the tested subjects, register transitions between voix mixte and falsetto were performed very continuously without clear register transition events. However, an increase of frequency and amplitude perturbation (jitter, relative average perturbation, and shimmer) was observed during register transitions.
These data suggest that professional tenors are able to avoid sudden registration events frequently observed in untrained voices.
Journal of voice: official journal of the Voice Foundation 05/2012; 26(5):674.e9-674.e15. · 0.95 Impact Factor
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ABSTRACT: The closed quotient, i.e., the ratio between the closed phase and the period, is commonly studied in voice research. However, the term may refer to measures derived from different methods, such as inverse filtering, electroglottography or high-speed digital imaging (HSDI). This investigation compares closed quotient data measured by these three methods in two boy singers. Each singer produced sustained tones on two different pitches and a glissando. Audio, electroglottographic signal (EGG), and HSDI were recorded simultaneously. The audio signal was inverse filtered by means of the decap program; the closed phase was defined as the flat minimum portion of the flow glottogram. Glottal area was automatically measured in the high speed images by the built-in camera software, and the closed phase was defined as the flat minimum portion of the area-signal. The EGG-signal was analyzed in four different ways using the matlab open quotient interface. The closed quotient data taken from the EGG were found to be considerably higher than those obtained from inverse filtering. Also, substantial differences were found between the closed quotient derived from HSDI and those derived from inverse filtering. The findings illustrate the importance of distinguishing between these quotients.
The Journal of the Acoustical Society of America 01/2012; 131(1):435-41. · 1.55 Impact Factor
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ABSTRACT: Voice periodicity during transitions from modal to falsetto register still remains an unclarified question.
We examined the acoustic and electroglottographic signals of 20 healthy untrained male voices' transitions from modal to falsetto register on the vowels /a, e, i, o, u, and æ/.
In addition to discontinuities in fundamental frequency (F0), an independent increase of jitter, relative average perturbation, and shimmer was observed during and apparently caused by the register transition. In falsetto, the jitter was higher than in the modal register. The contact quotient derived from the electroglottographic signal tended to be lower for higher than for lower F0.
Register transitions are associated with increase of perturbation.
Journal of voice: official journal of the Voice Foundation 11/2011; 25(6):663-9. · 0.95 Impact Factor
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MMW Fortschritte der Medizin 10/2011; 153(43):39-41.
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ABSTRACT: According to recent model investigations, vocal tract resonance is relevant to vocal registers. However, no experimental corroboration of this claim has been published so far. In the present investigation, ten professional tenors' vocal tract configurations were analyzed using MRI volumetry. All subjects produced a sustained tone on the pitch F4 (349 Hz) on the vowel /a/ (1) in modal and (2) in falsetto register. The area functions were estimated from the MRI data and their associated formant frequencies were calculated. In a second condition the same subjects repeated the same tasks in a sound treated room and their formant frequencies were estimated by means of inverse filtering. In both recordings similar formant frequencies were observed. Vocal tract shapes differed between modal and falsetto register. In modal as compared to falsetto the lip opening and the oral cavity were wider and the first formant frequency was higher. In this sense the presented results are in agreement with the claim that the formant frequencies differ between registers.
The Journal of the Acoustical Society of America 06/2011; 129(6):3955-63. · 1.55 Impact Factor
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ABSTRACT: Vocal stability throughout the passaggio region in professional singers is an unclarified area of research.
The acoustic and electroglottographic signals of ascending and descending frequency transitions from 220 to 440 Hz (and vice versa) on the vowels /a, e, i, o, u, æ/ were analyzed in eight professional tenors. The frequency transitions were accompanied by shifts in register conditions, from modal to unmodulated naïve falsetto and modal to voix mixte (and vice versa).
For ascending tasks, it was found that frequency perturbation values (jitter and relative average perturbation) were higher for the frequency transition and upper frequency produced in naïve falsetto or voix mixte compared with lower frequency produced in modal register. No such higher values were found for descending tasks. Shimmer was increased during frequency transitions between modal and naïve falsetto. The electroglottographic contact quotient showed a positive correlation with the sound pressure level for the modal register and voix mixte but not for the naïve falsetto.
In our study, ascending tasks, including register transitions, are different from descending tasks with regard to frequency perturbation in professional tenors.
Journal of voice: official journal of the Voice Foundation 05/2011; 26(4):440-6. · 0.95 Impact Factor
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ABSTRACT: Yodelling consists of changes in pitch, presumably produced in different vocal registers. It is often assumed that vocal tract configuration is important to vocal registers and thus also to yodelling. We analysed vocal tract configuration in yodelling with dynamic real-time MRI (8 frames/second) in two (female and male) Swiss yodellers and two (female and male) professional classical singers. MR profiles showed clearly different vocal tract shapes for lower (vowel /[Formula: see text]/) and upper pitch (vowel /u/) for both the yodellers and the singers. These differences were similar for yodellers but differed between both classical singers. When switching to the upper pitch the yodellers decreased their lip opening with nearly constant jaw opening, elevated the tongue dorsum, and widened the pharynx.
Logopedics, phoniatrics, vocology 03/2011; 36(3):109-13.
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ABSTRACT: Professional male altos (countertenors) mostly use a register function, which is considered to be derived from falsetto. However, the sound produced differs in professional altos compared with the modal register or falsetto of untrained voices. The aim of this study was to analyze differences of the vocal tract shapes in male alto register functions.
Dynamic real-time magnetic resonance imaging of eight frames per second was used to analyze the vocal tract profile in seven professional male altos who sang on the vowel /a/, an ascending and descending scale from G3 (196 Hz) to E4 (330 Hz). The scale included their register transition from modal register to stage (counter) falsetto and naïve falsetto.
Register transitions from modal register to stage falsetto were associated with increased lip opening, jaw retraction, elevation and back positioning of the tongue, pharynx narrowing, uvula elevation, drop of larynx height, and tilting of the larynx. Differences between stage and naïve falsetto were found mostly with regard to lip opening and pharynx width.
The differences between the vocal tract configurations might have an impact on the acoustic characteristics observed in professional male alto register functions.
Journal of voice: official journal of the Voice Foundation 03/2011; 25(6):670-7. · 0.95 Impact Factor
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ABSTRACT: Music performance anxiety (MPA) represents a high challenge every vocal performer has to meet. MPA can be defined on a continuum going from a low to a high level. MPA and its phenomena can be considered in terms of four levels: affect, cognition, behaviour, and physiology. A study carried out on seven opera singers and two instrumentalists during performance situations showed highly elevated values for the performers' heart rate and blood pressure. This study, as several others, yielded no clear evidence pointing to a correspondence between the level of anxiety and of physiological arousal. At the end of the article a multimodal approach to the treatment of MPA is illustrated consisting of different psychotherapeutic and body-oriented methods.
Logopedics, phoniatrics, vocology 12/2010; 35(4):175-82.
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ABSTRACT: Vocal fold oscillation patterns in vocal register transitions are still unclarified. The vocal fold oscillations and the open quotient were analyzed with high-speed digital imaging (HSDI) and electroglottography (EGG) in 18 male untrained subjects singing a glissando from modal to the falsetto register. Results reveal that the open quotient changed with register in both HSDI and EGG. The in-class correlations for different HSDI and EGG determinations of the open quotient were high. However, we found only weak interclass correlations between both methods. In 10 subjects, irregularities of vocal fold vibration occurred during the register transition. Our results confirm previous observations that falsetto register is associated with a higher open quotient compared with modal register. These data suggest furthermore that irregularities typically observed in audio and electroglottographic signals during register transitions are caused by irregularities in vocal fold vibration.
Journal of voice: official journal of the Voice Foundation 11/2010; 24(6):644-50. · 0.95 Impact Factor
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ABSTRACT: Yodelling is a special kind of vocal performance in traditional music which consists of rapid and repeated changes in pitch. It is assumed that these pitch changes are accompanied by register changes.
We analysed, using the laryngograph, yodelling on different vowels by four professional yodelling teachers (two male, two female), four professional classically trained singers, and four untrained voices.
Results reveal that pitch changes in yodelling are associated with decrease of electroglottograpgic (EGG) contact quotient for the upper pitch, indicating a register shift. Furthermore, in contrast to untrained voices, for the yodellers lower and upper pitches were more stable with respect to fundamental frequency and perturbation values, and the pitch transitions were faster.
Logopedics, phoniatrics, vocology 04/2010; 35(1):6-12.
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ABSTRACT: Tenor singers may reach their top pitch range either by shifting from modal to falsetto register or by using their so-called 'voix mixte'.
In this study, dynamic real-time MRI of 8 frames per second was used to analyze the vocal tract profile in 10 professional opera tenors, who sang an ascending scale from C4 (262 Hz) to A4 (440 Hz) on the vowel /a/. The scale included their register transition and the singers applied both register techniques in different takes.
Modal to falsetto register changes were associated with only minor vocal tract modifications, including elevation and tilting of the larynx and a lifted tongue dorsum. Transitions to voix mixte, by contrast, were associated with major vocal tract modifications. Under these conditions, the subjects widened their pharynges, their lip and jaw openings, and increased their jaw protrusion. These modifications were stronger in more 'heavy' tenors than in more 'light' tenors. The acoustic consequences of these articulatory changes are discussed.
Folia Phoniatrica et Logopaedica 01/2010; 62(6):278-87. · 1.12 Impact Factor
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Journal of otolaryngology - head & neck surgery = Le Journal d'oto-rhino-laryngologie et de chirurgie cervico-faciale 03/2009; 38(1):E19-22. · 0.71 Impact Factor
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ABSTRACT: Laryngeal dysfunction after thyroidectomy is a common complication. However, few data are available to differentiate whether these complications result from injury to the recurrent nerve or to the vocal folds from intubation.
University medical center.
Seven hundred sixty-one patients who underwent surgery to the thyroid gland from 1990 to 2002. Of these patients, 8.4% underwent a revision thyroidectomy.
Preoperative and postoperative laryngostroboscopic examination.
Laryngostroboscopic evaluation of laryngeal complications.
The overall rate of laryngeal complications was 42.0% (320 patients). Complications from an injury to the vocal folds occurred in 31.3% of patients. Weakness or paresis of the recurrent nerve was initially present in 6.6% and was related to the nerves at risk. This rate was higher in revision thyroidectomies than in primary surgical interventions (6.2% vs 11.6%; P = .04). The rate of laryngeal injuries was higher in patients older than 65 years (39.8% vs 30.8%; P = .03).
These data suggest that laryngeal complications after thyroidectomies are primarily caused by injury to the vocal folds from intubation and to a lesser extent by injury to the laryngeal nerve. We recommend documentation of informed consent, especially for patients who use their voice professionally, such as singers, actors, or teachers.
Archives of surgery (Chicago, Ill.: 1960) 03/2009; 144(2):149-53; discussion 153. · 4.32 Impact Factor
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ABSTRACT: The area of vocal registers is still unclarified. In a previous investigation, dynamic real-time magnetic resonance imaging (MRI), which is able to produce up to 10 frames per second, was successfully applied for examinations of vocal tract modifications in register transitions in male singers. In the present study, the same MRI technique was used to study vocal tract shapes during four professional young sopranos' lower and upper register transitions. The subjects were asked to sing a scale on the vowel /a/ across their transitions. The transitions were acoustically identified by four raters. In neither of these transitions, clear vocal tract changes could be ascertained. However, substantial changes, that is, widening of the lips, opening of the jaw, elevation of the tongue dorsum, and continuous widening of the pharynx, were observed when the singers reached fundamental frequencies that were close to the frequency of the first formant of the vowel sung. These findings suggest that in these subjects register transition was not primarily the result of modifications of the vocal tract.
Journal of voice: official journal of the Voice Foundation 02/2009; 24(2):133-9. · 0.95 Impact Factor
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Otolaryngology Head and Neck Surgery 07/2008; 138(6):805-6. · 1.72 Impact Factor
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ABSTRACT: To evaluate the feasibility of an optimized MRI protocol based on high field imaging at 3 T in combination with accelerated data acquisition by parallel imaging for the analysis of oropharyngeal and laryngeal function.
Fast 2D gradient echo (GRE) MRI with different spatial resolutions (1.7x2.7 and 1.1x1.5 mm2) and image update rates (4 and 10 frames per second) was employed to assess pharyngeal movements and visualize swallowing via tracking of an oral contrast bolus (blueberry juice). In a study with 10 normal volunteers, image quality was semi-quantitatively graded by three independent observers with respect to the delineation of anatomical detail and depiction of oropharynx and larynx function. Additionally, the feasibility of the technique for the visualization of pathological pre- and post-surgical oropharynx and larynx function was evaluated in a patient with inspiratory stridor.
Image grading demonstrated the feasibility of dynamic MRI for the assessment of normal oropharynx and larynx anatomy and function. Superior image quality (P<.05) was found for data acquisition with four frames per second and higher spatial resolution. In the patient, dynamic MRI detected pathological hypermobility of the epiglottis resulting in airway obstruction. Additional post-surgical MRI for one clinical case revealed morphological changes of the epiglottis and improved function, i.e., absence of airway obstruction and normal swallowing.
Results of the volunteer study demonstrated the feasibility of dynamic MRI at 3 T for the visualization of the oropharynx and larynx function during breathing, movements of the tongue and swallowing. Future studies are necessary to evaluate its clinical value compared to existing modalities based on endoscopy or radiographic techniques.
Magnetic Resonance Imaging 07/2008; 27(1):48-54. · 1.99 Impact Factor
