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Vocal fold vibratory characteristics in normal female speakers from high-speed digital imaging

Ahmad K, Yan Y, Bless DM

J Voice, 2012 Mar;26(2):239-53.
PMID: 21621975 DOI: 10.1016/j.jvoice.2011.02.001

The purpose of the study was to investigate relationships between vocal fold vibrations and voice quality. Laryngeal images obtained from high-speed digital imaging (HSDI) were examined for their open-closed timing characteristics and perturbation values. A customized software delineated the glottal edges and used the Hilbert transform-based method of analysis to provide objective quantification of glottal perturbation. Overlay tracings of the transformed glottal cycles provided visual patterns on the overall vibratory dynamics. In this paper, we described the use of this method in looking at vibratory characteristics of a group of young female speakers (N=23). We found that, females with no voice complaints and who had been perceived to have normal voices were not a homogeneous group in terms of their glottal vibratory patterns during phonation. Their vibratory patterns showed characteristics similar to exemplar voices targeted to be clear (50%), pressed (27%), breathy (15%), or a mixed quality (8%). Perturbation range in terms of cycle-to-cycle frequency and amplitude was small and did not discriminate patterns. All these patterns yielded perceptually normal voices suggesting that in normal young speakers, the level of perturbation may be more important to the judgment than the actual pattern of closure.

Matched MeSH terms: Vocal Cords/physiology*
Quantitative laryngeal electromyography (LEMG) in unilateral vocal fold paralysis: Developing normative values using the opposite normal mobile vocal fold

Chen IHK, Remli R, Azman M, Ubaidah MA, Mohamed AS, Baki MM

Auris Nasus Larynx, 2021 Dec;48(6):1140-1149.
PMID: 33896673 DOI: 10.1016/j.anl.2021.03.028

OBJECTIVE: Laryngeal electromyography (LEMG) is used to confirm neuropathy; traditionally, it is evaluated qualitatively. This study aimed to develop normative values for the thyroarytenoid-lateral cricoarytenoid (TA-LCA) muscle complex by determining the mean turns (MT) and mean amplitudes (MA) using the opposite normal mobile vocal fold in unilateral vocal fold paralysis (VFP). This study also compared the MT and MA of the paralyzed vocal fold with that of the normal side and analyzed their correlations.
METHODS: This is a cross-sectional study in which 77 patients (18 males, 59 females, mean age of 48) with unilateral VFP with an opposite normal mobile vocal fold underwent LEMG with a standardized protocol. Koufman gradings and MT and MA were used for the qualitative and quantitative evaluations. Mann-Whitney U test was performed to compare the median of the turns and amplitudes between the opposite normal mobile vocal fold and the paralyzed side. A linear-scale graphical "cloud" of the normal TA-LCA muscle complex was generated using logarithmic regression analysis. The qualitative and quantitative parameters were analyzed using multiple analysis of variance and Kruskall-Wallis test. Post-hoc analysis was performed to further determine the differences of the significance between both parameters. The correlation between the qualitative and quantitative parameters was analyzed using Spearman correlation.
RESULTS: The MT and MA were significantly higher for the normal TA-LCA muscle complex than the paralyzed side (582 vs. 336; 412 vs. 296, respectively) and the median of the turns and amplitudes were significantly lower in the paralyzed side with p-values <0.001. A significant difference was observed between the Koufman grading and the combination of MT and MA [F (8,144) = 73.254] and between the Koufman grading and MT and MA individually [H (4, 72) = 18.3 and H (4, 72) =33.4], in which both had p-values <0.001. A moderate negative linear relationship was seen between the Koufman grading and MT and MA. On further analysis, it was revealed that only certain pairs of Koufman grading were statistical significant.
CONCLUSIONS: This study was the first to present the quantitative normative values and "cloud" of the TA-LCA muscle complex using the opposite normal mobile vocal fold in patients with unilateral VFP in which it is comparable to healthy controls. We concluded that quantitative LEMG supports the qualitative Koufman grading method however it cannot be used independently to determine the severity of neuropathy.

Matched MeSH terms: Vocal Cords/physiology*
Fulltext Should clinical normality be examined in medical course?

Tiong TS

Singapore Med J, 2008 Apr;49(4):328-32.
PMID: 18418526

INTRODUCTION: In medical practice, some patients consult doctors for reassurance of normality, e.g. patients with throat discomfort. Therefore, medical graduates should be competent in diagnosing clinical normality. One way to assess clinical competence is by the objective structured clinical examination (OSCE).
METHODS: In 2002-2006, five batches of medical students who completed their otorhinolaryngology posting in Universiti Malaysia Sarawak were examined with the same OSCE question on clinically normal vocal cords. There were five subquestions concerning structures, clinical features, diagnosis and management. All students had prior slide show sessions regarding normal and abnormal laryngeal conditions.
RESULTS: The total number of students in 2002, 2003, 2004, 2005 and 2006 was 25, 41, 20, 30 and 16, respectively, and 100 percent responded. The average percentage of students with correct answers was 19.4, 2.4, 2.2, 21.2, and 2.4, in the subquestions 0.1 to 0.5, respectively, leaving the remaining relatively larger percentages with incorrect answers of various clinical abnormalities. A reason for these findings is examination fever by the students, who also assumed that all the stations had clinical abnormalities and required differentiating abnormalities from abnormalities, and not from normality. Without clinical normality OSCE questions, the assessment of the undergraduates' clinical competence in real life would seem incomplete.
CONCLUSION: This study showed that a significantly large percentage of students answered incorrectly in the clinical normality OSCE. This may mean that more clinical normality OSCE questions should be included in the undergraduate medical examination to help undergraduates practise the need to look for, and become competent in, clinical normality in real life.

Matched MeSH terms: Vocal Cords/physiology
Vocal fold vibratory characteristics of healthy geriatric females--analysis of high-speed digital images

Ahmad K, Yan Y, Bless D

J Voice, 2012 Nov;26(6):751-9.
PMID: 22633334 DOI: 10.1016/j.jvoice.2011.12.002

A high proportion of the geriatric population suffers from presbylaryngis and presbyphonia; however, our knowledge of vibratory patterns in this population is almost nonexistent. In this study, we investigate the vocal fold vibratory patterns of healthy elderly females to determine which features or combination of them could best describe the geriatric voices.

Matched MeSH terms: Vocal Cords/physiology*