| 1. |
- Andrade, Pedro Amarante, et al.
(författare)
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The Flow and Pressure Relationships in Different Tubes Commonly Used for Semi-occluded Vocal Tract Exercises
- 2016
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Ingår i: Journal of Voice. - : Mosby-Elsevier. - 0892-1997 .- 1873-4588. ; 30:1, s. 36-41
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Tidskriftsartikel (refereegranskat)abstract
- This experimental study investigated the back pressure (Pback) versus flow (U) relationship for 10 different tubes commonly used for semi-occluded vocal tract exercises, that is, eight straws of different lengths and diameters, a resonance tube, and a silicone tube similar to a Lax Vox tube. All tubes were assessed with the free end in air. The resonance tube and silicone tube were further assessed with the free end under water at the depths from 1 to 7 cm in steps of 1 cm. The results showed that relative changes in the diameter of straws affect Pback considerably more compared with the same amount of relative change in length. Additionally, once tubes are submerged into water, Pback needs to overcome the pressure generated by the water depth before flow can start. Under this condition, only a small increase in Pback was observed as the flow was increased. Therefore, the wider tubes submerged into water produced an almost constant Pback determined by the water depth, whereas the thinner straws in air produced relatively large changes to Pback as flow was changed. These differences may be taken advantage of when customizing exercises for different users and diagnoses and optimizing the therapy outcome.
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| 2. |
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| 4. |
- Baker, C. P., et al.
(författare)
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CPPS and Voice-Source Parameters : Objective Analysis of the Singing Voice
- 2022
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Ingår i: Journal of Voice. - : Elsevier BV. - 0892-1997 .- 1873-4588.
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: In recent years cepstral analysis and specific cepstrum-based measures such as smoothed cepstral peak prominence (CPPS) has become increasingly researched and utilized in attempts to determine the extent of overall dysphonia in voice signals. Yet, few studies have extensively examined how specific voice-source parameters affect CPPS values. Objective: Using a range of synthesized tones, this exploratory study sought to systematically analyze the effect of fundamental frequency (fo), vibrato extent, source-spectrum tilt, and the amplitude of the voice-source fundamental on CPPS values. Materials and Methods: A series of scales were synthesised using the freeware Madde. Fundamental frequency, vibrato extent, source-spectrum tilt, and the amplitude of the voice-source fundamental were systematically and independently varied. The tones were analysed in PRAAT, and statistical analyses were conducted in SPSS. Results: CPPS was significantly affected by both fo and source-spectrum tilt, independently. A nonlinear association was seen between vibrato extent and CPPS, where CPPS values increased from 0 to 0.6 semitones (ST), then rapidly decreased approaching 1.0 ST. No relationship was seen between the amplitude of the voice-source fundamental and CPPS. Conclusion: The large effect of fo should be taken into account when analyzing the voice, particularly in singing-voice research, when comparing pre and posttreatment data, and when comparing inter-subject CPPS data.
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| 5. |
- Baptista La, Filipa Martins, et al.
(författare)
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Pregnancy and the Singing Voice : Reports From a Case Study
- 2012
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Ingår i: Journal of Voice. - : Elsevier BV. - 0892-1997 .- 1873-4588. ; 26:4, s. 431-439
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. Significant changes in body tissues occur during pregnancy; however, literature concerning the effects of pregnancy on the voice is sparse, especially concerning the professional classically trained voice. Hypotheses. Hormonal variations and associated bodily changes during pregnancy affect phonatory conditions, such as vocal fold motility and glottal adduction. Design. Longitudinal case study with a semiprofessional classically trained singer. Methods. Audio, electrolaryngograph, oral pressure, and air flow signals were recorded once a week during the last 12 weeks of pregnancy, 48 hours after birth and during the following consecutive 11 weeks. Vocal tasks included diminuendo sequences of the syllable /pae/sung at various pitches, and performing a Lied. Phonation threshold pressures (PTPs) and collision threshold pressures (CTPs), normalized amplitude quotient (NAQ), alpha ratio, and the dominance of the voice source fundamental were determined. Concentrations of sex female steroid hormones were measured on three occasions. A listening test of timbral brightness and vocal fatigue was carried out. Results. Results demonstrated significantly elevated concentrations of estrogen and progesterone during pregnancy, which were considerably reduced after birth. During pregnancy, CTPs and PTPs were high; and NAQ, alpha ratio, and dominance of the voice source fundamental suggested elevated glottal adduction. In addition, a perceptible decrease of vocal brightness was noted. Conclusions. The elevated CTPs and PTPs during pregnancy suggest reduced vocal fold motility and increased glottal adduction. These changes are compatible with expected effects of elevated concentrations of estrogen and progesterone on tissue viscosity and water retention.
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| 6. |
- Beka, Ervin, et al.
(författare)
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Voice Changes Without Laryngeal Nerve Alterations After Thyroidectomy: The Need For Prospective Trials - A Review Study
- 2024
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Ingår i: Journal of Voice. - : MOSBY-ELSEVIER. - 0892-1997 .- 1873-4588. ; 38:1, s. 231-238
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Forskningsöversikt (refereegranskat)abstract
- Background. Thyroidectomy is a commonly performed surgical procedure that is offered for different thyroid pathologies. The most frequent complication after total thyroidectomy is transient or permanent hypoparathyroidism followed by transient or permanent recurrent laryngeal nerve palsy. Patients may experience voice impairment despite intact laryngeal nerve function. These patients are of special interest because they experience subjective symptoms which are difficult to measure and therefore to treat. Summary. The Voice Handicap Index (VHI) and VHI-10 are the most commonly used subjective questionnaires. Their results correlate with objective findings. Female sex, in particular after menopause, is a dominant factor for developing voice impairment after thyroidectomy. The extent of neck surgery and the weight and volume of the removed thyroid correlates directly with both objective and subjective voice impairment after surgery. Videolaryngostroboscopy should be considered to examine vocal cord pathologies in this patient group. Surprisingly, there are no studies showing that speech and voice therapy are beneficial for patients with voice alterations but with intact laryngeal nerves. Conclusions. While recurrent laryngeal nerve (RLN) paralysis can be evaluated by objective exams postoperatively, we are still left with the issue of possible partial or complete external branch of superior laryngeal nerve (EBSLN) injury. It is therefore quite difficult to segregate neural (RLN and EBSLN) and non -neural voice change populations, regardless of the method of literature evaluation. Perhaps patients' perspectives on how they experience voice functionality should play a superior role in deciding which patients should be investigated further with laryngoscopy, acoustic or perceptual analysis, and which patients should be offered treatment.
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| 8. |
- Björklund, Staffan, et al.
(författare)
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Relationship Between Subglottal Pressure and Sound Pressure Level in Untrained Voices
- 2016
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Ingår i: Journal of Voice. - : Elsevier BV. - 0892-1997 .- 1873-4588. ; 30:1, s. 15-20
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. Subglottal pressure (P-s) is strongly correlated with sound pressure level (SPL) and is easy to measure by means of commonly available equipment. The SPL/Ps ratio is strongly dependent on the efficiency of the phonatory apparatus and should be of great relevance to clinical practice. However, published normative data are still missing. Method. The subjects produced sequences of the syllable [pae], and P-s was measured as the oral pressure during the [p] occlusion. The P-s to SPL relationship was determined at four pitches produced by 16 female and 15 male healthy voices and analyzed by means of regression analysis. Average correlation between P-s and SPL, average SPL produced with a P-s of 10 cm H2O, and average SPL increase produced by a doubling of P-s were calculated for the female and for the male subjects. The significance of sex and pitch conditions was analyzed by means of analysis of variance (ANOVA). Results. Pitch was found to be an insignificant condition. The average correlation between P-s and SPL was 0.83 and did not differ significantly between the female and male subjects. In female and male subjects, P-s = 10 cm H2O produced 78.1 dB and 80.0 dB SPL at 0.3 m, and a doubling of P-s generated 11.1 dB and 9.3 dB increase of SPL. Both these gender differences were statistically significant. Conclusions. The relationship between P-s and SPL can be reliably established from series of repetitions of the syllable [pae] produced with a continuously changing degree of vocal loudness. Male subjects produce slightly higher SPL for a given pressure than female subjects but gain less for a doubling of P-s. As these relationships appear to be affected by phonation type, it seems possible that in the future, the method can be used for documenting degree of phonatory hypofunction and hyperfunction.
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| 9. |
- Björkner, Eva
(författare)
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Musical theater and opera singing - Why so different? : A study of subglottal pressure, voice source, and formant frequency characteristics
- 2008
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Ingår i: Journal of Voice. - : Elsevier BV. - 0892-1997 .- 1873-4588. ; 22:5, s. 533-540
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Tidskriftsartikel (refereegranskat)abstract
- The considerable voice timbre differences between musical theater (MT) and western operatic singers are analyzed with respect to voice source and formant frequencies in five representatives of each singer group. Audio, subglottal pressure (P(sub)), and electroglottograph (EGG) signals were recorded while the subjects sang a sequence of [pae:] syllables starting at maximal vocal loudness and then gradually decreasing vocal loudness. The task was performed at each of two fundamental frequencies (F(0)), approximately one octave apart. Ten equally spaced P(sub) values were then selected for each F(0). The subsequent vowels were analyzed in terms of flow glottograms derived by inverse filtering the audio signal, which also yielded formant frequency data. Period time (T(0)), peak-to-peak pulse amplitude (U(p-t-p)), and maximum flow declination rate (MFDR) were measured from the flow glottograms while closed quotient Q(closed) (T(cl)/T(0)) was determined in combination with the differentiated EGG signal. Also the relationship between the first and the second harmonic in the spectrum (H(1)-H(2)), the amplitude quotient (AQ), that is, the ratio between U(p-t-p) and MFDR, and normalized AQ, that is, AQ normalized with respect to period time was calculated as well as the sound pressure level. The results showed that both the MT and the opera singers varied their P(sub) systematically, approximately doubling P(sub) for a doubling of F(0). For a given value of P(sub), the MT singers produced higher values of MFDR, U(p-t-p), and Q(closed), and lower values of H(1)-H(2), indicating a weaker fundamental. Further, the MT singers showed higher formant frequencies and did not show the opera singers' characteristic clustering of F(3), F(4), and F(5).
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| 10. |
- Björkner, Eva, et al.
(författare)
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Voice source differences between registers in female musical theater singers
- 2006
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Ingår i: Journal of Voice. - : Elsevier BV. - 0892-1997 .- 1873-4588. ; 20:2, s. 187-197
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Tidskriftsartikel (refereegranskat)abstract
- Musical theater singing typically requires women to use two vocal registers. Our investigation considered voice source and subglottal pressure P-s characteristics of the speech pressure signal recorded for a sequence of /pae/ syllables sung at constant pitch and decreasing vocal loudness in each register by seven female musical theater singers. Ten equally spaced P-s values were selected, and the relationships between P-s and several parameters were examined; closed-quotient (Q(closed)), peak-to-peak pulse amplitude (Up-t-p), amplitude of the negative peak of the differentiated flow glottogram. ie, the maximum flow declination rate (MFDR), and the normalized amplitude quotient (NAQ) [Up-t-p/(TO*MFDR)], where TO is the fundamental period. P, was typically slightly higher in chest than in head register. As P, influences the measured glottogram parameters, these were also compared at an approximately identical P-s of 11 cm H2O. Results showed that for typical tokens, MFDR and Q(closed) were significantly greater, whereas Up-t-p and therefore NAQ were significantly lower in chest than in head.
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