| 1. |
- Echternach, Matthias, et al.
(author)
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High-Speed Imaging and Electroglottography Measurements of the Open Quotient in Untrained Male Voices' Register Transitions
- 2010
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In: Journal of Voice. - : Elsevier BV. - 0892-1997 .- 1873-4588. ; 24:6, s. 644-650
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Journal article (peer-reviewed)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 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.
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| 2. |
- Echternach, Matthias, et al.
(author)
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Perturbation Measurements in Untrained Male Voices' Transitions From Modal to Falsetto Register
- 2011
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In: Journal of Voice. - : Elsevier BV. - 0892-1997 .- 1873-4588. ; 25:6, s. 663-669
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Journal article (peer-reviewed)abstract
- Purpose. Voice periodicity during transitions from modal to falsetto register still remains an unclarified question. Method. 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 ae/. Results. 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. Conclusion. Register transitions are associated with increase of perturbation.
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| 3. |
- Echternach, Matthias, et al.
(author)
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Professional Opera Tenors' Vocal Tract Configurations in Registers
- 2010
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In: Folia Phoniatrica et Logopaedica. - : S. Karger AG. - 1021-7762 .- 1421-9972. ; 62:6, s. 278-287
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Journal article (peer-reviewed)abstract
- Objective: Tenor singers may reach their top pitch range either by shifting from modal to falsetto register or by using their so-called 'voix mixte'. Material and Methods: 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. Results: 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.
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| 4. |
- Echternach, Matthias, et al.
(author)
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Vocal fold vibrations at high soprano fundamental frequencies
- 2013
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In: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966 .- 1520-8524. ; 133:2, s. EL82-EL87
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Journal article (peer-reviewed)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 1568Hz human vocal folds do exhibit oscillations with complete closure. Therefore, the recent results suggest that human voice production at very high F0s up to 1568Hz is not caused by turbulence, but rather by airflow modulation from vocal fold oscillations. (C) 2013 Acoustical Society of America
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| 5. |
- Echternach, Matthias, et al.
(author)
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Vocal tract area functions and formant frequencies in opera tenors' modal and falsetto registers
- 2011
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In: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966 .- 1520-8524. ; 129:6, s. 3955-3963
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Journal article (peer-reviewed)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.
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| 6. |
- Echternach, Matthias, et al.
(author)
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Vocal Tract in Female Registers : A Dynamic Real-Time MRI Study
- 2010
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In: Journal of Voice. - : Elsevier BV. - 0892-1997 .- 1873-4588. ; 24:2, s. 133-139
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Journal article (peer-reviewed)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.
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| 7. |
- Mecke, Ann-Christine, et al.
(author)
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Comparing closed quotient in children singers' voices as measured by high-speed-imaging, electroglottography and inverse filtering
- 2012
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In: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966 .- 1520-8524. ; 131:1, s. 435-441
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Journal article (peer-reviewed)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.
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