Machine learning based estimation of hoarseness severity using sustained vowelsa).

Auditory perceptual evaluation is considered the gold standard for assessing voice quality, but its reliability is limited due to inter-rater variability and coarse rating scales. This study investigates a continuous, objective approach to evaluate hoarseness severity combining machine learning (ML) and sustained phonation. For this purpose, 635 acoustic recordings of the sustained vowel /a/ and subjective ratings based on the roughness, breathiness, and hoarseness scale were collected from 595 subjects. A total of 50 temporal, spectral, and cepstral features were extracted from each recording and used to identify suitable ML algorithms. Using variance and correlation analysis followed by backward elimination, a subset of relevant features was selected. Recordings were classified into two levels of hoarseness, H<2 and H≥2, yielding a continuous probability score y∈[0,1]. An accuracy of 0.867 and a correlation of 0.805 between the model's predictions and subjective ratings was obtained using only five acoustic features and logistic regression (LR). Further examination of recordings pre- and post-treatment revealed high qualitative agreement with the change in subjectively determined hoarseness levels. Quantitatively, a moderate correlation of 0.567 was obtained. This quantitative approach to hoarseness severity estimation shows promising results and potential for improving the assessment of voice quality.

Formant-Aware Spectral Analysis of Sustained Vowels of Pathological Breathy Voice.

OBJECTIVES: This paper reports the effectiveness of formant-aware spectral parameters to predict the perceptual breathiness rating. A breathy voice has a steeper spectral slope and higher turbulent noise than a normal voice. Measuring spectral parameters of acoustic signals over lower formant regions is a known approach to capture the properties related to breathiness. This study examines this approach by testing the contemporary spectral parameters and algorithms within the framework, alternate frequency band designs, and vowel effects. METHODS: Sustained vowel recordings (/a/, /i/, and /u/) of speakers with voice disorders in the German Saarbrueken Voice Database were considered (n: 367). Recordings with signal irregularities, such as subharmonics or with roughness perception, were excluded from the study. Four speech language pathologists perceptually rated the recordings for breathiness on a 100-point scale, and their averages were used in the analysis. The acoustic spectra were segmented into four frequency bands according to the vowel formant structures. Five spectral parameters (intraband harmonics-to-noise ratio, HNR; interband harmonics ratio, HHR; interband noise ratio, NNR; and interband glottal-to-noise energy, GNE, ratio) were evaluated in each band to predict the perceptual breathiness rating. Four HNR algorithms were tested. RESULTS: Multiple linear regression models of spectral parameters, led by the HNRs, were shown to explain up to 85% of the variance in perceptual breathiness ratings. This performance exceeded that of the acoustic breathiness index (82%). Individually, the HNR over the first two formants best explained the variances in the breathiness (78%), exceeding the smoothed cepstrum peak prominence (74%). The performance of HNR was highly algorithm dependent (10% spread). Some vowel effects were observed in the perceptual rating (higher for /u/), predictability (5% lower for /u/), and model parameter selections. CONCLUSIONS: Strong per-vowel breathiness acoustic models were found by segmenting the spectrum to isolate the portion most affected by breathiness.

Computational fluid dynamics model of laryngotracheal stenosis and correlation to pulmonary function measures.

3D models of airway lumens were created from CT scans of 19 patients with laryngotracheal stenosis. Computational fluid dynamics (CFD) simulations were completed for each, and results were compared to measured peak inspiratory flow rate, grade of lumen constriction, and measures of airway geometry. Results demonstrate flow resistance and shear stress correlate with degree of lumen constriction and absolute cross-sectional area as well as flow rate. Flow recirculation depends on airway constriction but does not vary with flow rate. Resistance and wall shear stress did not correlate well with functional measures. Flow recirculation did differ between subjects with higher functional measures and subjects with lower functional measures. This analysis provides mathematical models to predict airway resistance, wall shear stress, and flow reversal according lumen constriction and inspiratory flow rate. It suggests aerodynamic factors such as flow recirculation play a role in differences in functional performance between patients with similar airway measures.

Pixel-Based Swallow Measurements: Correcting Nonsquare Pixels.

PURPOSE: This research note illustrates the effects of video data with nonsquare pixels on the pixel-based measures obtained from videofluoroscopic swallow studies (VFSS). METHOD: Six pixel-based distance and area measures were obtained from two different videoflouroscopic study units; both yielding videos with nonsquare pixels with different pixel aspect ratios (PARs). The swallowing measures were obtained from the original VFSS videos and from the videos after their pixels were squared. RESULTS: The results demonstrated significant multivariate effects both in video type (original vs. squared) and in the interaction between video type and sample (two video recordings of different patients, different PARs, and opposing tilt angles of the external reference). A wide range of variabilities was observed on the pixel-based measures between original and squared videos with the percent deviation ranging from 0.1% to 9.1% with the maximum effect size of 7.43. CONCLUSIONS: This research note demonstrates the effect of disregarding PAR to distance and area pixel-based parameters. In addition, we present a multilevel roadmap to prevent possible measurement errors that could occur. At the planning stage, the PAR of video source should be identified, and, at the analyses stage, video data should be prescaled prior to analysis with PAR-unaware software. No methodology in prior absolute or relative pixel-based studies reports adjustment to the PAR prior to measurements nor identify the PAR as a possible source of variation within the literature. Addressing PAR will improve the precision and stability of pixel-based VFSS findings and improve comparability within and across clinical and research settings. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.21957134.

Investigation of Vocal Bifurcations and Voice Patterns Induced by Asymmetry of Pathological Vocal Folds.

PURPOSE: Vocal fold asymmetry creates irregular entrainments and modulations in voice, which may lead to rough perceptual quality. The presence of asymmetry can also cause mid-phonation bifurcations where a small change in the phonatory system causes a drastic change in vibration pattern, resulting in transitions in and out of rough voice. This study surveys sustained phonation recordings of speakers with the diagnoses of vocal fold polyp or unilateral vocal fold paralysis to investigate the resulting voice patterns. METHOD: This retrospective study observed 71 sustained phonation recordings from 48 patients. Segments with distinctive signal patterns were identified within each recording with narrowband spectrogram and computer-assisted analysis of spectral peaks. RESULTS: Phonation segmentation yielded 240 segments across all the recordings. Five voice patterns were recognized: (regularly or irregularly) entrained, modulated, uncoupled, unstable, and pulsed. Thirty-six patients (75%) exhibited irregular patterns. No single irregular pattern lasted for the entire phonation and was always accompanied by at least one mid-phonation bifurcation. Durations of the irregular segments (M = 0.4 s) were significantly shorter than the segments with the regular pattern (M = 1.4 s). CONCLUSIONS: The results suggest that vocal fold pathology frequently introduces dynamic vibratory patterns that affect both the acoustic signals and perceptions. Due to these abnormalities, it is important for clinical voice assessment protocols, both perceptual and acoustic, to account for these possible bifurcations, irregular signal patterns, and their tendencies.

Harmonics-to-noise ratio estimation with deterministically time-varying harmonic model for pathological voice signals.

The harmonics-to-noise ratio (HNR) and other spectral noise parameters are important in clinical objective voice assessment as they could indicate the presence of nonharmonic phenomena, which are tied to the perception of hoarseness or breathiness. Existing HNR estimators are built on the voice signals to be nearly periodic (fixed over a short period), although voice pathology could induce involuntary slow modulation to void this assumption. This paper proposes the use of a deterministically time-varying harmonic model to improve the HNR measurements. To estimate the time-varying model, a two-stage iterative least squares algorithm is proposed to reduce model overfitting. The efficacy of the proposed HNR estimator is demonstrated with synthetic signals, simulated tremor signals, and recorded acoustic signals. Results indicate that the proposed algorithm can produce consistent HNR measures as the extent and rate of tremor are varied.

Re-Training of Convolutional Neural Networks for Glottis Segmentation in Endoscopic High-Speed Videos.

Endoscopic high-speed video (HSV) systems for visualization and assessment of vocal fold dynamics in the larynx are diverse and technically advancing. To consider resulting "concepts shifts" for neural network (NN)-based image processing, re-training of already trained and used NNs is necessary to allow for sufficiently accurate image processing for new recording modalities. We propose and discuss several re-training approaches for convolutional neural networks (CNN) being used for HSV image segmentation. Our baseline CNN was trained on the BAGLS data set (58,750 images). The new BAGLS-RT data set consists of additional 21,050 images from previously unused HSV systems, light sources, and different spatial resolutions. Results showed that increasing data diversity by means of preprocessing already improves the segmentation accuracy (mIoU + 6.35%). Subsequent re-training further increases segmentation performance (mIoU + 2.81%). For re-training, finetuning with dynamic knowledge distillation showed the most promising results. Data variety for training and additional re-training is a helpful tool to boost HSV image segmentation quality. However, when performing re-training, the phenomenon of catastrophic forgetting should be kept in mind, i.e., adaption to new data while forgetting already learned knowledge.

A Deep Learning Enhanced Novel Software Tool for Laryngeal Dynamics Analysis.

Purpose High-speed videoendoscopy (HSV) is an emerging, but barely used, endoscopy technique in the clinic to assess and diagnose voice disorders because of the lack of dedicated software to analyze the data. HSV allows to quantify the vocal fold oscillations by segmenting the glottal area. This challenging task has been tackled by various studies; however, the proposed approaches are mostly limited and not suitable for daily clinical routine. Method We developed a user-friendly software in C# that allows the editing, motion correction, segmentation, and quantitative analysis of HSV data. We further provide pretrained deep neural networks for fully automatic glottis segmentation. Results We freely provide our software Glottis Analysis Tools (GAT). Using GAT, we provide a general threshold-based region growing platform that enables the user to analyze data from various sources, such as in vivo recordings, ex vivo recordings, and high-speed footage of artificial vocal folds. Additionally, especially for in vivo recordings, we provide three robust neural networks at various speed and quality settings to allow a fully automatic glottis segmentation needed for application by untrained personnel. GAT further evaluates video and audio data in parallel and is able to extract various features from the video data, among others the glottal area waveform, that is, the changing glottal area over time. In total, GAT provides 79 unique quantitative analysis parameters for video- and audio-based signals. Many of these parameters have already been shown to reflect voice disorders, highlighting the clinical importance and usefulness of the GAT software. Conclusion GAT is a unique tool to process HSV and audio data to determine quantitative, clinically relevant parameters for research, diagnosis, and treatment of laryngeal disorders. Supplemental Material https://doi.org/10.23641/asha.14575533.

Interdependencies between acoustic and high-speed videoendoscopy parameters.

In voice research, uncovering relations between the oscillating vocal folds, being the sound source of phonation, and the resulting perceived acoustic signal are of great interest. This is especially the case in the context of voice disorders, such as functional dysphonia (FD). We investigated 250 high-speed videoendoscopy (HSV) recordings with simultaneously recorded acoustic signals (124 healthy females, 60 FD females, 44 healthy males, 22 FD males). 35 glottal area waveform (GAW) parameters and 14 acoustic parameters were calculated for each recording. Linear and non-linear relations between GAW and acoustic parameters were investigated using Pearson correlation coefficients (PCC) and distance correlation coefficients (DCC). Further, norm values for parameters obtained from 250 ms long sustained phonation data (vowel /i/) were provided. 26 PCCs in females (5.3%) and 8 in males (1.6%) were found to be statistically significant (|corr.| ≥ 0.3). Only minor differences were found between PCCs and DCCs, indicating presence of weak non-linear dependencies between parameters. Fundamental frequency was involved in the majority of all relevant PCCs between GAW and acoustic parameters (19 in females and 7 in males). The most distinct difference between correlations in females and males was found for the parameter Period Variability Index. The study shows only weak relations between investigated acoustic and GAW-parameters. This indicates that the reduction of the complex 3D glottal dynamics to the 1D-GAW may erase laryngeal dynamic characteristics that are reflected within the acoustic signal. Hence, other GAW parameters, 2D-, 3D-laryngeal dynamics and vocal tract parameters should be further investigated towards potential correlations to the acoustic signal.

Predicting Need for Surgery in Recurrent Laryngotracheal Stenosis Using Changes in Spirometry.

OBJECTIVES/HYPOTHESIS: We sought to identify changes that occur in spirometric values between surgical interventions in patients with recurrent laryngotracheal stenosis and assess the utility of tracking those changes in predicting the need to return to surgery. METHODS: This is a retrospective, case-control study of laryngotracheal stenosis. Charts from a 10 year period were reviewed, and 80 patients were identified with recurrent laryngotracheal stenosis and serial spirometry. Recorded forced expiratory volume in 1 second (FEV1 ), forced inspiratory volume in 1 second (FIV1 ), peak expiratory flow (PEF), and peak inspiratory flow (PIF), and body mass index (BMI) were tabulated. Calculations were then performed to determine deviations in spirometric measurements from maximums. Comparing the patients who required intervention to those who did not, we used a regression analysis to generate a decision tree based on factors with the strongest predictive power. We then calculated receiver operating characteristic (ROC) curves for all calculated variables. RESULTS: Deviations in PEF, PIF, and FIV1 from each patient's maximums had strong predictive power in determining return to surgery. PIF was the only fixed measurement found to have a statistically significant role in predicting return to surgery. BMI did not play a role. CONCLUSION: For each patient, the deviation from their overall spirometric maximums had the statistically strongest predictive power in determining need to return to surgery. This suggests the importance of the trends in spirometric measures for each individual, and implies these trends have greater import than fixed measures alone. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:2199-2203, 2021.

BAGLS, a multihospital Benchmark for Automatic Glottis Segmentation.

Laryngeal videoendoscopy is one of the main tools in clinical examinations for voice disorders and voice research. Using high-speed videoendoscopy, it is possible to fully capture the vocal fold oscillations, however, processing the recordings typically involves a time-consuming segmentation of the glottal area by trained experts. Even though automatic methods have been proposed and the task is particularly suited for deep learning methods, there are no public datasets and benchmarks available to compare methods and to allow training of generalizing deep learning models. In an international collaboration of researchers from seven institutions from the EU and USA, we have created BAGLS, a large, multihospital dataset of 59,250 high-speed videoendoscopy frames with individually annotated segmentation masks. The frames are based on 640 recordings of healthy and disordered subjects that were recorded with varying technical equipment by numerous clinicians. The BAGLS dataset will allow an objective comparison of glottis segmentation methods and will enable interested researchers to train their own models and compare their methods.

Determination of Clinical Parameters Sensitive to Functional Voice Disorders Applying Boosted Decision Stumps.

BACKGROUND: Various voice assessment tools, such as questionnaires and aerodynamic voice characteristics, can be used to assess vocal function of individuals. However, not much is known about the best combinations of these parameters in identification of functional dysphonia in clinical settings. METHODS: This study investigated six scores from clinically commonly used questionnaires and seven acoustic parameters. 514 females and 277 males were analyzed. The subjects were divided into three groups: one healthy group (N01) (49 females, 50 males) and two disordered groups with perceptually hoarse (FD23) (220 females, 96 males) and perceptually not hoarse (FD01) (245 females, 131 males) sounding voices. A tree stumps Adaboost approach was applied to find the subset of parameters that best separates the groups. Subsequently, it was determined if this parameter subset reflects treatment outcome for 120 female and 51 male patients by pairwise pre- and post-treatment comparisons of parameters. RESULTS: The questionnaire "Voice-related-quality-of-Life" and three objective parameters ("maximum fundamental frequency", "maximum Intensity" and "Jitter Percent") were sufficient to separate the groups (accuracy ranging from 0.690 (FD01 vs. FD23, females) to 0.961 (N01 vs. FD23, females)). Our study suggests that a reduced parameter subset (4 out of 13) is sufficient to separate these three groups. All parameters reflected treatment outcome for patients with hoarse voices, Voice-related-quality-of-Life showed improvement for the not hoarse group (FD01). CONCLUSION: Results show that single parameters are insufficient to separate voice disorders but a set of several well-chosen parameters is. These findings will help to optimize and reduce clinical assessment time.

Predicting Swallowing Outcomes from Objective Videofluoroscopic Timing and Displacement Measures in Head and Neck Cancer Patients.

Radiation therapy with or without chemotherapy compromises swallowing efficiency and safety in patients with head and neck cancer (HNC). The resulting dysphagia leads to overall morbidity, with altered diets, reduced nutritional intake, reduced quality of life, and potential interruption of curative cancer treatment. Despite well-documented radiation-related changes in swallowing physiology, scarce research exists on the potential clinical value for measurements of swallowing timing and displacement in this population. This study investigated the discriminatory value of quantitative timing and displacement parameters for the Functional Oral Intake Scale and Penetration Aspiration Scale scores using pre- and post-radiation videofluoroscopy data. Swallowtail Software Version 1 (Belldev Medical, Arlington Heights, IL) was used to obtain objective timing and displacement measurements from the pre- and post-radiation videofluoroscopy data for 31 patients who underwent radiation therapy, with or without chemotherapy, for head and neck cancer. The total pharyngeal transit time (BP2) (p < 0.000, r = 0.43) in pudding bolus trials and the maximal upper esophageal sphincter opening (PESMax/cm) (p = 0.001, r = 0.31) in thin bolus trials were discriminatory for Functional Oral Intake Scale (FOIS). Findings suggest that measurement of post-radiation changes using objective and quantitative parameters may offer some discriminatory value regarding future dysphagia risk and prognosis based on total pharyngeal transit time and degree of UES opening. In addition, the results suggest that different bolus types may offer different discriminatory values in HNC population, and that some timing and displacement variables may have discriminatory value for patients' diet levels independent from any aspiration risk.

Voice Outcomes Following Multiple Surgeries for Recurrent Respiratory Papillomatosis.

OBJECTIVES: Recurrent Respiratory Papillomatosis (RRP) is a rare disease caused by the human papilloma virus that presents as warty, exophytic growths in the upper airway. RRP in the larynx can lead to severe airway obstruction and voice changes. It is clinically known that patients with RRP frequently experience dysphonia. The purpose of this study was to assess the impact of multiple surgical treatments on RRP patients' voice outcomes, and to determine whether a higher number of repeated surgeries lead to decreased voice quality. METHODS: A retrospective cohort study was conducted of adult RRP patients (n = 23) who underwent multiple surgeries. Group 1 included patients (n = 11) who had <5 surgeries (range 2-4 surgeries) and Group 2 included patients (n = 12) who had ≥5 surgeries (range 5-50+ surgeries). Voice recordings were selected from the following clinic visits: initial office visit (initial presurgery), first postsurgery, and the last clinic encounter(s) with no immediate planned surgery. Blinded auditory-perceptual ratings along with cepstral and spectral acoustic measures assessed voice severity. RESULTS: There was significant improvement from the initial presurgery visit compared to each postoperative visit over time for all voice outcome measures for both Group 1 and Group 2. The results of the study indicated that the number of surgeries did not significantly affect mean postoperative voice outcomes, and there were no significant differences between patient groups for voice quality over time. CONCLUSIONS: The results of this study suggest that RRP patients' voice quality may not suffer cumulative negative effects when using modern tissue-sparing surgical techniques.

Influence of spatial camera resolution in high-speed videoendoscopy on laryngeal parameters.

In laryngeal high-speed videoendoscopy (HSV) the area between the vibrating vocal folds during phonation is of interest, being referred to as glottal area waveform (GAW). Varying camera resolution may influence parameters computed on the GAW and hence hinder the comparability between examinations. This study investigates the influence of spatial camera resolution on quantitative vocal fold vibratory function parameters obtained from the GAW. In total 40 HSV recordings during sustained phonation (20 healthy males and 20 healthy females) were investigated. A clinically used Photron Fastcam MC2 camera with a frame rate of 4000 fps and a spatial resolution of 512×256 pixels was applied. This initial resolution was reduced by pixel averaging to (1) a resolution of 256×128 and (2) to a resolution of 128×64 pixels, yielding three sets of recordings. The GAW was extracted and in total 50 vocal fold vibratory parameters representing different features of the GAW were computed. Statistical analyses using SPSS Statistics, version 21, was performed. 15 Parameters showing strong mathematical dependencies with other parameters were excluded from the main analysis but are given in the Supporting Information. Data analysis revealed clear influence of spatial resolution on GAW parameters. Fundamental period measures and period perturbation measures were the least affected. Amplitude perturbation measures and mechanical measures were most strongly influenced. Most glottal dynamic characteristics and symmetry measures deviated significantly. Most energy perturbation measures changed significantly in males but were mostly unaffected in females. In females 18 of 35 remaining parameters (51%) and in males 22 parameters (63%) changed significantly between spatial resolutions. This work represents the first step in studying the impact of video resolution on quantitative HSV parameters. Clear influences of spatial camera resolution on computed parameters were found. The study results suggest avoiding the use of the most strongly affected parameters. Further, the use of cameras with high resolution is recommended to analyze GAW measures in HSV data.

Reliability of High-speed Videoendoscopic Ratings of Essential Voice Tremor and Adductor Spasmodic Dysphonia.

OBJECTIVES: The main objectives of this study were to (1) examine intrarater and inter-rater reliabilities in perceptual ratings of vocal fold vibratory patterns and supraglottic characteristics for essential vocal tremor and adductor spasmodic dysphonia (AdSD) using high-speed videoendoscopy (HSV), and (2) to investigate the specificity of the parameters in differentiating these two voice disorders. METHODS: HSV recordings of 34 cases diagnosed with essential vocal tremor, AdSD, or AdSD with vocal tremor were evaluated blindly by two voice speech pathologists. The two raters examined all HSV video segments twice across nine supraglottic and vocal fold vibratory characteristics for inter-rater and intrarater reliabilities. A separate consensus rating was then developed, with the results analyzed to explore differentiation. RESULTS: Raters demonstrated moderate intrarater reliability with mean Spearman's rho correlation coefficients of 0.68 (rater 1) and 0.73 (rater 2). Moderate inter-rater reliability for the two raters was seen across all parameters with a mean Cohen's kappa coefficient of 0.51. Raters showed higher intrarater and inter-rater reliabilities for supraglottic parameters. Only the presence of tremor differentiated between the two voice disorders in cases with a consistent diagnosis. CONCLUSIONS: The high level of concomitance between vocal tremor and AdSD may affect subjective perceptual analysis of supraglottic and vocal fold vibratory patterns. Results indicate similar global involvement of supraglottic laryngeal structures for both vocal tremor and AdSD.

Dependencies and Ill-designed Parameters Within High-speed Videoendoscopy and Acoustic Signal Analysis.

OBJECTIVE: The phonatory process is often judged during sustained phonation by analyzing the acoustic voice signal and the vocal fold vibrations. Many formulas and parameters have been suggested for qualifying the characteristics of the acoustic signal and the vocal fold vibrations during sustained phonation. These parameters are directly computed from the acoustic signal and the endoscopic glottal area waveform (GAW). The GAW is calculated from laryngeal high-speed videoendoscopy (HSV) recordings and describes the increase and decrease of the glottal area during the phonation process, that is, the opening and closing of the two oscillating vocal folds over time. However, some of the parameters have strong mathematical dependencies with one another and some are ill-defined. The purpose of this study is to identify mathematical dependencies between parameters with the aim of reducing their numbers and suggesting which parameters may best describe the properties of the GAW and the acoustical signal. METHODS: In this preliminary investigation, 20 frequently used parameters are examined: 10 GAW only and 10 both GAW and acoustic parameters. RESULTS: In total 13 parameters can be neglected because of mathematical dependencies. In addition, nine of these parameters show problematic features that range from unexpected behavior to ill definition. CONCLUSIONS: Reducing the number of parameters appears to be necessary to standardize vocal fold function analysis. This may lead to better comparability of research results from different studies.

Vocal Fold Vibration in Older Adults With and Without Age-Related Dysphonia.

Purpose: The purpose of this study was to identify the extent to which 7 measures of glottal area timing and regularity differ between older adults with and without age-related dysphonia (ARD). Method: Laryngeal high-speed videoendoscopy was completed at 4,000 frames per second for 42 adults aged 70 years and older (ARD: 9 female, 5 male; control group: 15 female, 13 male). Relative glottal gap, open quotient, speed index, maximum area declination rate, harmonics-to-noise ratio, harmonic richness factor, and standard deviation of fundamental frequency were measured from a 0.5-s segment of the glottal area waveform. Eta squared (η2) was computed to estimate group effect. Results: Small effect sizes (η2 = .18-.35) were present for relative glottal gap, open quotient, maximum area declination rate, harmonic richness factor, and standard deviation of fundamental frequency. Speed index and glottal harmonics-to-noise ratio did not explain group membership (η2 = .001 and .05, respectively). Conclusion: These findings provide evidence that vocal fold vibration in ARD is different than in normal aging, whereas the overlap in values for every measure is consistent with the concept that normal aging and ARD exist as a continuum of health and disease.

The Effects of the Menstrual Cycle on Vibratory Characteristics of the Vocal Folds Investigated With High-Speed Digital Imaging.

OBJECTIVES: This study investigated the effect of menstrual cycle on vocal fold vibratory characteristics in young women using high-speed digital imaging. This study examined the menstrual phase effect on five objective high-speed imaging parameters and two self-rated perceptual parameters. The effects of oral birth control use were also investigated. METHODS: Thirteen subjects with no prior voice complaints were included in this study. All data were collected at three different time periods (premenses, postmenses, ovulation) over the course of one menstrual cycle. For five of the 13 subjects, data were collected for two consecutive cycles. Six of 13 subjects were oral birth control users. From high-speed imaging data, five objective parameters were computed: fundamental frequency, fundamental frequency deviation, harmonics-to-noise ratio, harmonic richness factor, and ratio of first and second harmonics. They were supplemented by two self-rated parameters: Reflux Severity Index and perceptual voice quality rating. Analysis included mixed model linear analysis with repeated measures. RESULTS: Results indicated no significant main effects for menstrual phase, between-cycle, or birth control use in the analysis for mean fundamental frequency, fundamental frequency deviation, harmonics-to-noise ratio, harmonic richness factor, first and second harmonics, Reflux Severity Index, and perceptual voice quality rating. Additionally, there were no interaction effects. CONCLUSIONS: Hormone fluctuations observed across the menstrual cycle do not appear to have direct effect on vocal fold vibratory characteristics in young women with no voice concerns. Birth control use, on the other hand, may have influence on spectral richness of vocal fold vibration.

Effects of Volume, Pitch, and Phonation Type on Oscillation Initiation and Termination Phases Investigated With High-speed Videoendoscopy.

OBJECTIVES: This study aimed to investigate the effects of varying volume, pitch, and phonation types on the initiation and termination phases of vocal fold oscillation using high-speed digital videoendoscopy. Specifically, it addressed the effects of the variation of volume, pitch, and phonation type (normal, pressed, and breathy) on the transient duration of the vibrating glottal length (length transient duration, Tlen), the transient duration of the glottal area waveform (area transient duration, Tarea), the time offset between the beginning (or the end) of the full-length vibration and the full-amplitude vibration, TΔ, and the variation of the fundamental frequency during the vocal fold oscillation initiation and termination segments (pitch instability, %PI). METHODS: A female subject with no voice problem produced voices with varying pitch and loudness, including comfortable pitch and comfortable loudness, normal pitch loud, high pitch and comfortable loudness, and high pitch and loud. Breathy and pressed phonations were also recorded. Each of the six phonation types was recorded six times, which resulted in 72 transient segments (each recording included both initiation and termination phases). Mixed model statistical analyses were employed to the five objective high-speed digital videoendoscopy parameters. RESULTS: Preliminary findings demonstrated significant findings for voice type effects for the length and area transient durations for the oscillation initiation segment but not for the oscillation termination segment. CONCLUSIONS: This study demonstrates that voice types appear to influence vibration initiation patterns more than the vibration termination patterns.