Evaluation of Vertical Level Differences Between Left and Right Vocal Folds Using Artificial Intelligence System in Excised Canine Larynx.

OBJECTIVES: This study aimed to establish an artificial intelligence (AI) system to classify vertical level differences between vocal folds during vocalization and to evaluate the accuracy of the classification. METHODS: We designed models with different depths between the right and left vocal folds using an excised canine larynx. Video files for the data set were obtained using a high-speed camera system and a color complementary metal oxide semiconductor camera with global shutter. The data sets were divided into training, validation, and testing. We used 20,000 images for building the model and 8000 images for testing. To perform deep learning multiclass classification and to estimate the vertical level difference, we introduced DenseNet121-ConvLSTM. RESULTS: The model was trained several times using different numbers of epochs. We achieved the most optimal results at 100 epochs, and the batch size used during training was 16. The proposed DenseNet121-ConvLSTM model achieved classification accuracies of 99.5% and 88.0% for training and testing, respectively. After verification using an external data set, the overall accuracy, precision, recall, and f1-score were 90.8%, 91.6%, 90.9%, and 91.2%, respectively. CONCLUSIONS: The newly developed AI system may be an easy and accurate method for classifying superior and inferior vertical level differences between vocal folds. Thus, this AI system can be applied and may help in the assessment of vertical level differences in patients with unilateral vocal fold paralysis.

The Usefulness of Multi Voice Evaluation for Measuring Voice Recovery After Endolaryngeal Phonomicrosurgery in Patients with Vocal Fold Polyps.

OBJECTIVES: The purpose of this study was to the usefulness of a five-variable model predicting perceived voice severity and incorporating acoustic analysis based on cepstral analysis and self-reported questionnaires, for measuring voice recovery after endolaryngeal phonomicrosurgery in patients with vocal fold polyps. METHODS: In this study, 72 patients with vocal fold polyps were included. Two voice evaluations, including acoustic analysis, self-reported questionnaires, and auditory perceptual assessments for each patient, were implemented before and after endolaryngeal phonomicrosurgery. Using these evaluations, we compared the mean values of the perceptual evaluation of voice, acoustic analysis parameters, self-reported questionnaires, and the five-variable model estimated severity pre- and post-endolaryngeal phonomicrosurgery. RESULTS: Various parameters related to acoustic analysis, self-reported questionnaires, and auditory perceptual assessments were useful for measuring voice recovery after endolaryngeal phonomicrosurgery. In particular, a five-variable model incorporating spectral/cepstral analyses and self-reported questionnaires was able to effectively track voice changes after endolaryngeal phonomicrosurgery. CONCLUSION: We verified that most of the variables and the five-variable model were useful for measuring voice recovery in patients with vocal polyps after endolaryngeal phonomicrosurgery.

The Usefulness of Auditory Perceptual Assessment and Acoustic Analysis as a Screening Test for Voice Problems.

BACKGROUND/AIMS: The aims of study were (1) to determine the cut-off values of parameters related to auditory perceptual assessment (visual analog scale [VAS]) and acoustic analysis (cepstral peak prominence [CPP], low-frequency/high-frequency [L/H] ratio, CPP SD, L/H ratio SD, acoustic voice quality index [AVQI], and cepstral spectral index of dysphonia [CSID]) for predicting voice problems within a Korean population, and (2) to verify the discriminative power of these cut-off values. METHODS: 1,113 voice samples were analyzed in this study. Perceptual assessments (VAS) were performed by 5 speech-language pathologists. For the acoustic analysis, cepstral parameters, CSID, and AVQI were calculated. The cut-off values of parameters predicting voice problems were obtained using receiver operating characteristic (ROC) analysis. Additionally, the sensitivity, specificity, and area under the ROC curve (AUC) were measured. RESULTS: High reliabilities were observed for the perceptual assessments. The cut-off values of parameters had a high sensitivity, specificity, and AUC. Of these, CSID was the parameter with the highest AUC values. CONCLUSION: Each parameter demonstrated a high discriminative power for classifying the presence or absence of voice problems. The results of this study could be used as an objective criterion for screening voice problems.

The Usefulness of Auditory Perceptual Assessment and Acoustic Analysis for Classifying the Voice Severity.

OBJECTIVE: The aims of this study were to (1) to determine the cut-off values of parameters related to auditory perceptual assessment (visual analog scale) and acoustic analysis (cepstral peak prominence, low frequency/high frequency ratio, cepstral peak prominence standard deviation, low frequency/high frequency ratio standard deviation, acoustic voice quality index, and cepstral spectral index of dysphonia) for predicting the voice severity within a Korean population; and (2) to verify the discriminative power of these cut-off values. METHODS: Voice samples of 1,029 subjects who visited Pusan National University Hospital, South Korea to be treated for swallowing or voice evaluation from January 2018 to December 2018 were analyzed in this retrospective study. The acoustic analysis of cepstral parameters, cepstral spectral index of dysphonia, and acoustic voice quality index were calculated using the Computerized Speech Lab and Praat software. The cut-off values of parameters predicting the voice severities were obtained using receiver operating characteristic analysis. Through this analysis, the sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were measured. RESULTS: High reliabilities of auditory perceptual assessments were observed for the auditory perceptual assessment. The cut-off values of parameters predicting voice severities had high sensitivity, specificity, and area under the curve. CONCLUSIONS: The cut-off values of parameters predicting the voice severities demonstrated a high power to discriminate for classifying the voice severities within a Korean population. The results of this study could be used as objective criteria to screen for severities of voice disorders.

Comparison of Two Versions of the Acoustic Voice Quality Index for Quantification of Dysphonia Severity.

OBJECTIVES: The acoustic voice quality index (AVQI) is a specific acoustic indicator designed to objectively estimate dysphonia severity and measure the values of acoustic parameters based on the diagnostic category. This study compared the performance of two AVQI versions (2.02 and 3.01, v2 and v3) and PraatCPPS using a voice sample of Korean population. MATERIALS AND METHODS: Voice samples for sustained vowel and connected speech were elicited from 2257 patients across 14 diagnostic categories. Auditory-perceptual (A-P) assessments of dysphonia severity were compared to acoustic parameters of severity derived from two versions of the AVQI (v2 and v3) as well as the PraatCPPS. RESULTS: The AVQI-estimated severity (v2 and v3) and PraatCPPS severity for concatenated voice samples strongly correlated with each other and were significantly associated with A-P ratings. The AVQI (v2 and v3) and PraatCPPS showed high reliability in differentiating between pathological voice disorders. CONCLUSION: The AVQI (v2 and v3) and PraatCPPS were strongly correlated with the A-P ratings and provided valid estimates of dysphonia severity. However, the associations of the A-P ratings with the AVQIv2 were significantly stronger than those with the AVQIv3 and PraatCPPS, suggesting that the V2 outperformed the V3 and PraatCPPS.

Clinical Application of Two-Dimensional Scanning Digital Kymography in Discrimination of Diplophonia.

Purpose The purpose of this study was to investigate the characteristics of diplophonia using an auditory perception and multimodal simultaneous examination, which included sound waveform analysis, electroglottography (EGG), digital kymography (DKG), and 2-dimensional scanning digital kymography (2D DKG). Additionally, we compared the diagnostic accuracy of each method using a binary classifier in confusion matrix and convenience of discrimination, based on the time required for interpretation. Method One normophonic male, 12 patients with diplophonia, and 12 dysphonia patients without diplophonia were enrolled. A multimodal simultaneous evaluation was used to analyze the vibration pattern of diplophonia. Sensitivity, specificity, accuracy, area under the curve, and interpretation time were used to compare the various diagnostic methods. Discrimination was determined by 3 raters. Results There are 3 types of asymmetric vibratory patterns in diplophonia. The types are based on the oscillators vibrating at different frequencies: asymmetry of the left and right cords (6 subjects with unilateral palsy and 1 subject with vocal polyps), asymmetry of anterior and posterior cords (2 subjects with vocal polyps), and asymmetry of true and false cords (3 subjects with muscle tension dysphonia). All evaluation methods were useful as diagnostic tools, with all areas under the curve > .70. The diagnostic accuracy was highest with DKG (95.83%), followed by 2D DKG (83.33%), EGG (81.94%), auditory-perceptual evaluation (80.56%), and sound waveform (77.78%). The interpretation time was the shortest for auditory-perceptual evaluation (6.07 ± 1.34 s), followed by 2D DKG (10.04 ± 3.00 s), EGG (12.49 ± 2.76 s), and DKG (13.53 ± 2.60 s). Conclusions Auditory-perceptual judgment was the easiest and fastest method for experienced raters, but its diagnostic accuracy was lower than that of DKG or 2D DKG. The diagnostic accuracy of DKG was the highest, but 2D DKG allowed rapid interpretation and showed relatively high diagnostic accuracy, except in cases with space-occupying lesions. Supplemental Material https://doi.org/10.23641/asha.9911786.

Voice Recovery in a Patient with Inhaled Laryngeal Burns.

INTRODUCTION: Laryngeal burns cause long-term voice disorders due to mucosal changes of the vocal folds. Inhalation injuries affect voice production and result in changes in the mucosal thickness and voice quality. CASE REPORT: A 47-year-old woman was transferred to our department with laryngeal burns sustained during a house fire. On laryngoscopic examination, mucosal waves of both vocal folds were not visualized due to the injury caused by inhalation of high-temperature toxic smoke. Hence, voice analysis, laryngoscopic examinations, and high-speed videoendoscopy (HSV) were performed to evaluate vocal fold vibrations. An absence of mucosal waves and a breathy and strained voice with a severe grade were noted. We report that voice quality was recovered to close to the normal state through multiple treatments such as medication, voice therapy, and counseling. CONCLUSION: This paper presents the unique case of a patient with laryngeal burns, in which vibrations of the vocal folds were observed using laryngoscopic examination and HSV. Voice samples before and after treatment were also analyzed. By observing the vibration pattern of the injured vocal fold, it is expected that appropriate diagnosis and treatment planning can be established in clinical practice.

Validation of the Acoustic Voice Quality Index in the Korean Language.

OBJECTIVE: The purpose of this study was to explore the concurrent validity of the Acoustic Voice Quality Index (AVQI) in a Korean population. We investigated the feasibility of its cutoff values and diagnostic accuracy in discriminating between normal and dysphonic voices. MATERIALS AND METHODS: A total of 1,524 native Korean subjects with normal voices (n = 113) and with voice disorders (n = 1,411) were asked to speak and sustain the vowel "a" and to read the Korean text "Walk" aloud. A 2-second mid-speech portion of the sustained vowel sound and two sentences (with 26 syllables) were edited and concatenated, and the AVQI was calculated. Additionally, two auditory-perceptual assessments, namely the Grade, Roughness, Breathiness, Asthenia, Strain scale, and the Consensus Auditory-Perceptual Evaluation of Voice were used by five speech language pathologists to rate the severity of dysphonia. RESULTS: Both auditory-perceptual assessments showed high confidence levels among the five speech language pathologists. The AVQI correlated with grade (G) and overall severity (OS). There were statistically significant differences in AVQI, G, and OS between normal and pathological speech groups. In the receiver operating characteristic curve analysis, AVQI, G, and OS cutoff values were <3.33, <0.00, and <22.00, respectively. The receiver operating characteristic curve analysis indicated that AVQI had excellent diagnostic accuracy for discriminating between normal and dysphonic voices (area under the curve: 0.970-0.977). CONCLUSIONS: We demonstrated the concurrent validity of AVQI as a promising tool for assessing overall voice quality and quantifying dysphonia in a Korean-speaking population.

Usefulness of Two-Dimensional Digital Kymography in Patients With Vocal Fold Scarring.

OBJECTIVE: Although laryngeal videostroboscopy is widely utilized in the analysis of vocal fold vibrations, it is often difficult to identify patterns of vocal fold vibrations in patients with aperiodic voice signals due to failure of synchronization during laryngeal videostroboscopy examination. Therefore, the present study aimed to compare the usefulness of simultaneous two-dimensional digital kymography (2D DKG) and traditional DKG for the detection of changes in the pattern of vocal fold vibrations in patients with vocal fold scarring (VFS). METHODS: Seven patients with VFS and one normal subject underwent high-speed videoendoscopy (HSV). DKG and 2D DKG evaluations of vocal fold vibrations were performed simultaneously, following which both qualitative and quantitative analyses were performed. RESULTS: Simultaneous DKG and 2D DKG enabled observation of vibratory patterns as well as amplitude and phase symmetry. DKG revealed and provided temporal information regarding the pattern of vocal fold vibrations at sites of VFS. In contrast, 2D DKG provided real-time information regarding the pattern of vibrations for the whole vocal fold region and regions of increased stiffness, as well as spatial information regarding changes in this pattern. CONCLUSION: Our findings indicate that 2D DKG enables the assessment of overall vocal fold vibrations, regardless of periodicity, and that simultaneous DKG and 2D DKG can be used to confirm abnormal patterns of vocal fold vibrations in patients with impaired flexibility and elasticity of the vocal folds.

Effects of Injection Laryngoplasty with Hyaluronic Acid in Patients with Vocal Fold Paralysis.

OBJECTIVES: The purpose of this study was to explore the effects of injection laryngoplasty (IL) with hyaluronic acid in patients with vocal fold paralysis (VFP). METHODS: A total of 50 patients with VFP participated in this study. Pre- and post-IL assessments were performed, which included analyzing the sustained vowel /a/ phonation, and the patient reading 1 Korean sentence from the "Walk" passage that comprised 25 syllables in 10 words. To investigate the effect of IL on vocal fold function, acoustic analysis (acoustic voice quality index, cepstral peak prominence, maximum phonation time, speaking fundamental frequency) was conducted and auditory-perceptual (grade and overall severity), visual judgment (gap), and self-questionnaire (voice handicap index-10) assessments were performed. RESULTS: The patients with VFP showed statistically significant differences between pre-and post-IL assessments for acoustic and auditory-perception, visual judgment, and self-questionnaire assessments. CONCLUSION: The patients with VFP showed positive change in vocal fold function between pre- and post-IL measurements. The findings showed that IL with hyaluronic acid is an effective method to improve vocal fold function in patients with VFP.

Real-time dual visualization of two different modalities for the evaluation of vocal fold vibration - Laryngeal videoendoscopy and 2D scanning videokymography: Preliminary report.

OBJECTIVE: Currently, various tools have been introduced for the assessment of vocal fold vibration: laryngeal videolaryngoscopy (LV), videokymography (VKG), high speed videoendoscopy (HSV), digital videokymography (DKG), and 2D scanning videokymography (2D VKG). Among these, the authors have recently designed a dual modality examination system using LV and 2D VKG for more detailed information regarding the vibrations of the vocal folds. The clinical availability of this hybrid system offers medical imaging departments a range of potential advantages in the evaluation of vocal fold vibration. The obvious benefit of simultaneous acquisition is the improved integration of information that allows not only optimal anatomic localization, but also physical movement patterns. Other advantages include the lessened inconvenience to patients due to no longer requiring repeated examinations and shortening the examination time, and increased profitability. The purpose of study was to identify the efficacy of real-time dual examination of two different modalities for the evaluation of vocal fold vibration in human subjects and vocal fold vibration simulator. METHODS: One vocally healthy subject and three patients with vocal fold nodules, a vocal cyst, and vocal fold paralysis took part in this study. The vibratory patterns of the vocal folds were visualized using simultaneous real-time examination of two different modalities. Additionally, qualitative and quantitative analyses of the dual LV and 2D VKG images were performed. RESULTS: Real-time dual examination using a two modality system provided high definition images of the vibratory movements of the vocal folds. By assessing the obtained images, we confirmed that the dual modality examination method was useful in the evaluation of pathologic vibratory patterns, even in non-periodic phonation. CONCLUSION: The present system might improve the understanding of the processes of vocal fold vibration and make a contribution to pathologic voice research, as well as clinical practice.

Selective detection of viable Helicobacter pylori using ethidium monoazide or propidium monoazide in combination with real-time polymerase chain reaction.

Because Helicobacter pylori has a role in the pathogenesis of gastric cancer, chronic gastritis and peptic ulcer disease, detection of its viable form is very important. The objective of this study was to optimize a PCR method using ethidium monoazide (EMA) or propidium monoazide (PMA) for selective detection of viable H. pylori cells in mixed samples of viable and dead bacteria. Before conducting the real-time PCR using SodB primers of H. pylori, EMA or PMA was added to suspensions of viable and/or dead H. pylori cells at concentrations between 1 and 100 µM. PMA at a concentration of 50 µM induced the highest DNA loss in dead cells with little loss of genomic DNA in viable cells. In addition, selective detection of viable cells in the mixtures of viable and dead cells at various ratios was possible with the combined use of PMA and real-time PCR. In contrast, EMA penetrated the membranes of both viable and dead cells and induced degradation of their genomic DNA. The findings of this study suggest that PMA, but not EMA, can be used effectively to differentiate viable H. pylori from its dead form.

Proteomic analysis of heat-stable proteins in Escherichia coli.

Some proteins of E. coli are stable at temperatures significantly higher than 49 degrees C, the maximum temperature at which the organism can grow. The heat stability of such proteins would be a property which is inherent to their structures, or it might be acquired by evolution for their specialized functions. In this study, we describe the identification of 17 heat-stable proteins from E. coli. Approximately one-third of these proteins were recognized as having functions in the protection of other proteins against denaturation. These included chaperonin (GroEL and GroES), molecular chaperones (DnaK and FkpA) and peptidyl prolyl isomerases (trigger factor and FkpA). Another common feature was that five of these proteins (GroEL, GroES, Ahpc, RibH and ferritin) have been shown to form a macromolecular structure. These results indicated that the heat stability of certain proteins may have evolved for their specialized functions, allowing them to cope with harsh environments, including high temperatures.