Characteristics of Vocal Fold Vibrations in Vocally Healthy Subjects: Analysis With Multi-Line Kymography

Abstract

PURPOSE In this study, the authors aimed to analyze longitudinal data from high-speed digital images in normative subjects using multi-line kymography. METHOD Vocally healthy subjects were divided into young (9 men and 17 women; Mage = 27 years) and older groups (8 men and 12 women; Mage = 73 years). From high-speed digital images of phonation at a conversational frequency kymograms were created at 5 different levels of the vocal fold and were analyzed to determine the opening/closing longitudinal phase difference, open quotient, and speed index. Then age- and gender-related differences of these parameters were analyzed statistically. RESULTS Young women frequently showed a pattern of posterior-to-anterior glottal opening and anterior-to-posterior glottal closure, and older women demonstrated various opening and closing patterns. Both young men and older men were similar to older women. The open quotient was maximal at the most posterior glottal level in young women, but it tended to be maximal at the anterior glottis in the other subgroups. The mean value of the 5 open quotients was largest in young women. The mean speed index had a large negative value in older subjects. CONCLUSION This study provides the first information about age-related differences of longitudinal oscillatory characteristics of the vocal folds obtained with high-speed digital imaging.

Quantitative Analysis of Digital Videokymography: A Preliminary Study on Age- and Gender-Related Difference of Vocal Fold Vibration in Normal Speakers

“…5,39 The minor variation in monitored longitudinal level can lead to altered speed quotient, as well. 12,38 Speed quotient mean was smaller in the elderly subjects than young subjects. This age-associated decrease in the speed quotient mean may originate from structural and functional alteration of the vocal fold resulting from geriatric change, leading to the decreased speed of vocal folds returning to the midline.…”

“…In this study, the open quotient was found to be 0.55 ± 0.15 at a speaking F 0 at the midpoint of the membranous portion, which generally matched the values in some previous reports, 23,28,31,38,39 but was rather smaller than those in other reports (Table 7). 5,20 These differences may stem from differences in the data acquisition technique (videostroboscopy 23,39 or HSDI 28,31,38 ), the method of analysis (DKG, 31,38 glottal width waveform, 5 or glottal area waveform 39 ), monitored longitudinal level, 12,38 or variation in the examination conditions. According to previous reports, open quotient increases as F 0 increases and decreases as the intensity increases.…”

“…9,10,[23][24][25]31 DKG was selected in the present study because it was one of the serial HSDI researches on normophonic subjects. 11,12,32,33 Advantages of DKG included normalization by VFL which facilitates parametric comparison with videostroboscopic studies that frequently use size normalization by VFL. [34][35][36] Normalization by VFL also allows parameterization of more various vibratory characteristics (eg, amplitude, mucosal wave, or IGW).…”

“…Through recent advances, this technique has since developed into videokymography (VKG) 14 and (DKG). 12 Strobovideokymography, which is based on a videostroboscopic technique, is also available, 15 but it is less widely used than VKG and DKG, presumably because of providing less reliable assessment than that obtained with the high frame rates of these other methods.…”

“…These approaches include the glottal width waveform, 5 glottal area waveform, 6 phonovibrography, 7 laryngotopography, [8][9][10][11] and digital kymography (DKG). 12 Among these techniques, DKG analysis is considered to be the best choice for evaluating the temporal characteristics of HSDI data.…”