Vocal Fold Vibration of the Whistle Register Observed by High-Speed Digital Imaging.

INTRODUCTION: Singers use a whistle register to sing at a fundamental frequency above 1000 Hz. In previous studies, vocal fold vibrations with or without complete closure and partial vocal fold vibrations were observed depending on the subject. However, the production mechanism of the whistle register is not yet clearly understood because of the limitations of the imaging device for the glottis and subjects. OBJECTIVES: This study aims to examine vocal fold vibrations in a whistle register. METHODS: The dynamic behavior of the glottis was recorded for six singers (four females and two males) using a high-speed digital imaging device with a frame rate above 10,000 fps. Audio signals were recorded simultaneously. The data were analyzed in the form of topography, glottal area waveforms, spectrograms, and phonovibrography to examine spatiotemporal patterns of glottal motion. RESULTS: The vibratory motion of the vocal folds was classified into six patterns. The first pattern was the entire vocal fold vibration with complete closure during the closed phase. The second to fifth was the entire vocal fold vibration without complete closure, where a gap was observed for the full length of the vocal folds for the second, at the posterior part of the glottis for the third, at the anterior for the fourth, and at both ends for the fifth. In the sixth pattern, the vocal folds vibrated partially. Our results support the previous findings on the vibration of the vocal folds. In addition, we identified novel vibratory patterns in the vocal folds. CONCLUSION: We conclude that the production of the whistle register is not just an extension of the falsetto register to the higher fundamental-frequency region; rather, the production mechanism of the whistle register appeared to be diverse as a means of vocalization.

Dynamic Analysis Of Male "Extra-high Voice" Using Multi-row Detector Computed Tomography.

OBJECTIVES/HYPOTHESIS: Some people who practice singing on a daily basis may be able to produce a voice higher than the upper limit of the normal range (extra high voice), but there is much regarding the movement of the larynx that remains unknown. We have been conducting dynamic analysis of the larynx using multi-row detection computed tomography (MD-CT) at our university and report herein an analysis of the extra high voice. STUDY DESIGN: Observational. METHODS: Images of a normal male participant capable of extremely high-frequency speech (the highest speech range is C7 [2093 Hz] and the singing application range is up to B5 [988 Hz]) during speech were captured by MD-CT. The acquisition time was 2 seconds, and the rise of the voice from low to high and then to very high tones was recorded. Ten frames per second were analyzed as three-dimensional images. RESULTS: In the fundamental frequency range from A3 to D5 (220-587 Hz), laryngeal elevation movements were observed as the voice rose in pitch. However, posterior upward displacement of the laryngeal cartilage was observed as the frequency range increased from E5 to B5 (659-988 Hz). CONCLUSIONS: In the E5-B5 range, laryngeal movements were different from those observed in the previous range. MD-CT analysis is useful in the study of this range because it allows visualization of laryngeal movements that are unclear using endoscopy or external examination.

Differences Among Mixed, Chest, and Falsetto Registers: A Multiparametric Study.

INTRODUCTION: Typical singing registers are the chest and falsetto; however, trained singers have an additional register, namely, the mixed register. The mixed register, which is also called "mixed voice" or "mix," is an important technique for singers, as it can help bridge from the chest voice to falsetto without noticeable voice breaks. OBJECTIVE: The present study aims to reveal the nature of the voice-production mechanism of the different registers (chest, mix, and falsetto) using high-speed digital imaging (HSDI), electroglottography (EGG), and acoustic and aerodynamic measurements. STUDY DESIGN: Cross-sectional study. METHODS: Aerodynamic measurements were acquired for twelve healthy singers (six men and women) during the phonation of a variety of pitches using three registers. HSDI and EGG devices were simultaneously used on three healthy singers (two men and one woman) from which an open quotient (OQ) and speed quotient (SQ) were detected. Audio signals were recorded for five sustained vowels, and a spectral analysis was conducted to determine the amplitude of each harmonic component. Furthermore, the absolute (not relative) value of the glottal volume flow was estimated by integrating data obtained from the HSDI and aerodynamic studies. RESULTS: For all singers, the subglottal pressure (PSub) was the highest for the chest in the three registers, and the mean flow rate (MFR) was the highest for the falsetto. Conversely, the PSub of the mix was as low as the falsetto, and the MFR of the mix was as low as the chest. The HSDI analysis showed that the OQ differed significantly among the registers, even when the fundamental frequency was the same; the OQ of the mix was higher than that of the chest but lower than that of the falsetto. The acoustic analysis showed that, for the mix, the harmonic structure was intermediate between the chest and falsetto. The results of the glottal volume-flow analysis revealed that the maximum volume velocity was the least for the mix register at every fundamental frequency. The first and second harmonic (H1-H2) difference of the voice source spectrum was the greatest for the falsetto, then the mix, and finally, the chest. CONCLUSIONS: We found differences in the registers in terms of the aeromechanical mechanisms and vibration patterns of the vocal folds. The mixed register proved to have a distinct voice-production mechanism, which can be differentiated from those of the chest or falsetto registers.

Automatic GRBAS Scoring of Pathological Voices using Deep Learning and a Small Set of Labeled Voice Data.

OBJECTIVES: Auditory-perceptual evaluation frameworks, such as the grade-roughness-breathiness-asthenia-strain (GRBAS) scale, are the gold standard for the quantitative evaluation of pathological voice quality. However, the evaluation is subjective; thus, the ratings lack reproducibility due to inter- and intra-rater variation. Prior researchers have proposed deep-learning-based automatic GRBAS score estimation to address this problem. However, these methods require large amounts of labeled voice data. Therefore, this study investigates the potential of automatic GRBAS estimation using deep learning with smaller amounts of data. METHODS: A dataset consisting of 300 pathological sustained /a/ vowel samples was created and rated by eight experts (200 for training, 50 for validation, and 50 for testing). A neural network model that predicts the probability distribution of GRBAS scores from an onset-to-offset waveform was proposed. Random speed perturbation, random crop, and frequency masking were investigated as data augmentation techniques, and power, instantaneous frequency, and group delay were investigated as time-frequency representations. RESULTS: Five-fold cross-validation was conducted, and the automatic scoring performance was evaluated using the quadratic weighted Cohen's kappa. The results showed that the kappa values of the automatic scoring performance were comparable to those of the inter-rater reliability of experts for all GRBAS items and the intra-rater reliability of experts for items G, B, A, and S. Random speed perturbation was the most effective data augmentation technique overall. When data augmentation was applied, power was the most effective for items G, R, A, and S; for Item B, combining group delay and power yielded additional performance gains. CONCLUSION: The automatic GRBAS scoring achieved by the proposed model using scant labeled data was comparable to that of experts. This suggests that the challenges resulting from insufficient data can be alleviated. The findings of this study can also contribute to performance improvements in other tasks such as automatic voice disorder detection.

Tracheoesophageal Diversion and Puncture for Preserving Phonation in Intractable Aspiration: A Case Series.

OBJECTIVE/HYPOTHESIS: Tracheoesophageal diversion (TED) can prevent damage to the respiratory system in patients with swallowing disorders and/or repetitive aspiration pneumonia; however, TED may cause the loss of phonation. Our previous study demonstrated that TED with tracheoesophageal puncture (TEP) prevents aspiration while retaining phonation. In this study, we aimed to further evaluate the feeding status and phonation of patients who underwent TED with TEP to verify the reproducibility of this procedure. STUDY DESIGN: Case series study. METHODS: We retrospectively reviewed the medical records of 11 patients who underwent TED with TEP for intractable aspiration from February 2017 to August 2019 at Fukuoka Sanno Hospital. We evaluated the preoperative penetration aspiration score (PPAS), daily activities, preoperative and postoperative food intake level scale (FILS) score, nutrition route, maximum phonation time(MPT), and postoperative communication method. RESULTS: The study population included 10 men and 1 woman (mean age, 66 years; range, 44-81) with a PPAS of 6.8 ± 1.0. The FILS score changed from 2.1 ± 0.5 preoperatively to 7.5 ± 2.0 postoperatively (paired t-test, P < .05), while the MPT changed from 7.9 ± 4.1 to 10.3 ± 4.2 s (paired t-test, P = .9). Preoperatively, a gastric fistula (eight patients [73%]) was the main nutrition route, followed by a gastric tube (two patients [18%]). Postoperatively, the main nutritional route for eight patients (73%) was oral, while the remaining three patients (27%) used the oral route occasionally. All patients maintained laryngeal phonation function, and eight (73%) used only laryngeal phonation for communication. CONCLUSIONS: Patients with intractable aspiration who wish to retain phonatory function should be advised to undergo TED with TEP. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1965-E1970, 2021.

Tracheoesophageal diversion improves oral uptake of food: a retrospective study.

PURPOSE: Tracheoesophageal diversion (TED) is an effective therapeutic procedure for intractable aspiration. In this study, we performed TED in cases of intractable aspiration and/or repetitive pneumonia, investigated the main route of nutritional uptake after the procedure, and evaluated the swallowing method using videofluoroscopy. We also evaluated the validity of TED for treating intractable aspiration. METHODS: We retrospectively reviewed 44 patients (30 male and 14 female patients; median age, 55 years; range 15-85 years) who underwent TED for the treatment of intractable aspiration between January 2008 and December 2017. We examined the route of nutritional uptake before and after the operation and performed videofluoroscopy to detect the swallowing method after the operation. RESULTS: The percentage of patients with oral intake increased from 21% (9/44) before TED to 56% (25/44) within 1 month after TED (p < 0.01); this percentage included patients with poor preoperative swallowing function. Overall, 60% patients who were able to communicate and mobilize using a wheelchair as well as 92% patients who were able to communicate and mobilize in the supine position were able to consume food orally. We subsequently performed videofluoroscopy in 24 of the 25 patients with oral intake and assessed the passage route of the contrast agent, which was found to move through the laryngeal route in 54% of these patients. CONCLUSION: TED may be suitable for the treatment of intractable aspiration and can improve oral intake, particularly in patients with good mobility and communication ability.

Single injection of basic fibroblast growth factor to treat severe vocal fold lesions and vocal fold paralysis.

OBJECTIVES/HYPOTHESIS: Severe vocal fold lesions such as vocal fold sulcus, scars, and atrophy induce a communication disorder due to severe hoarseness, but a treatment has not been established. Basic fibroblast growth factor (bFGF) therapies by either four-time repeated local injections or regenerative surgery for vocal fold scar and sulcus have previously been reported, and favorable outcomes have been observed. In this study, we modified bFGF therapy using a single of bFGF injection, which may potentially be used in office procedures. STUDY DESIGN: Retrospective chart review. METHODS: Five cases of vocal fold sulcus, six cases of scars, seven cases of paralysis, and 17 cases of atrophy were treated by a local injection of bFGF. The injection regimen involved injecting 50 µg of bFGF dissolved in 0.5 mL saline only once into the superficial lamina propria using a 23-gauge injection needle. Two months to 3 months after the injection, phonological outcomes were evaluated. RESULTS: The maximum phonation time (MPT), mean airflow rate, pitch range, speech fundamental frequency, jitter, and voice handicap index improved significantly after the bFGF injection. Furthermore, improvement in the MPT was significantly greater in patients with (in increasing order) vocal fold atrophy, scar, and paralysis. The improvement in the MPT among all patients was significantly correlated with age; the MPT improved more greatly in younger patients. CONCLUSIONS: Regenerative treatments by bFGF injection­even a single injection­effectively improve vocal function in vocal fold lesions. LEVEL OF EVIDENCE: 4