Simplified Vocal Efficiency Metrics Normalize Following Voice Therapy in Subgroups of Patients With Nonphonotraumatic Vocal Hyperfunction.

Purpose: The purpose of this study is to determine whether simplified vocal efficiency (VE) metrics could accurately identify changes after voice therapy in individuals with nonphonotraumatic vocal hyperfunction (NPVH). This study analyzes treatment-related changes for traditional VE-vocal intensity (square of sound pressure) over aerodynamic power-and three simplified VE ratios: (a) sound pressure level over aerodynamic power (SPL/AP), (b) SPL over subglottal pressure (SPL/Ps), and (c) SPL over airflow (SPL/AFLOW).

Method: Retrospective data from 108 adults (80 females, 28 males) diagnosed with primary muscle tension dysphonia (associated with NPVH) and 208 vocally healthy adults (181 females, 27 males).

Comparing ambulatory voice measures during daily life with brief laboratory assessments in speakers with and without vocal hyperfunction.

The most common types of voice disorders are associated with hyperfunctional voice use in daily life. Although current clinical practice uses measures from brief laboratory recordings to assess vocal function, it is unclear how these relate to an individual's habitual voice use. The purpose of this study was to quantify the correlation and offset between voice features computed from laboratory and ambulatory recordings in speakers with and without vocal hyperfunction.

Subject-Specific Modeling by Domain Adaptation for the Estimation of Subglottal Pressure from Neck-Surface Acceleration Signals.

Subglottal air pressure is a critical physiologically-based parameter that reveals fundamental pathophysiological processes in patients with voice disorders. However, its assessment in both laboratory and ambulatory settings presents significant challenges due to the necessity for specialized instruments, invasive procedures, and the impracticality of direct measurement in ambulatory contexts. This study expands upon previous efforts to estimate subglottal pressure from portable, lightweight neck-surface acceleration signals using a physiologically relevant model of voice production combined with machine learning techniques.

Effects of Recording Condition and Number of Monitored Days on the Discriminative Power of the Daily Phonotrauma Index.

Purpose: The Daily Phonotrauma Index (DPI) can quantify pathophysiological mechanisms associated with daily voice use in individuals with phonotraumatic vocal hyperfunction (PVH). Since DPI was developed based on weeklong ambulatory voice monitoring, this study investigated if DPI can achieve comparable performance using (a) short laboratory speech tasks and (b) fewer than 7 days of ambulatory data.

Method: An ambulatory voice monitoring system recorded the vocal function/behavior of 134 females with PVH and vocally healthy matched controls in two different conditions.

Characterizing Vocal Hyperfunction Using Ecological Momentary Assessment of Relative Fundamental Frequency.

Many common voice disorders are associated with vocal hyperfunction (VH), with subtypes including phonotraumatic VH (leading to organic vocal fold lesions such as nodules and/or polyps) and nonphonotraumatic VH (often diagnosed as primary muscle tension dysphonia). VH has been hypothesized to influence baseline vocal fold tension during phonation, and the relative fundamental frequency (RFF) during onset and offset cycles of phonation has been related to vocal fold tension and has been shown to differentiate typical voices from patients with VH in laboratory settings. In this study, we investigated whether the laboratory sensitivity of RFF to the presence of VH found in the laboratory is preserved in naturalistic, in-field settings and whether ecological momentary assessment of RFF during daily life could be a correlate of self-reported vocal effort.

Vocal Fold Dissipated Power in Females with Hyperfunctional Voice Disorders.

Objective: Phonotrauma has been hypothesized to be associated with prolonged and/or accumulated biomechanical stress on vocal fold tissue. This hypothesis can be tested using ambulatory monitoring of vocal fold dissipated power, which requires a reliable method for its noninvasive estimation during the activity of daily living. The first aim of this study was to show that a laboratory-based estimate of vocal fold dissipated power computed from intraoral pressure (IOP) has significant discriminative power in individuals with phonotraumatic vocal hyperfunction (PVH).

Floating Ball Voice Therapy: Preliminary Effects on Outcomes and Predicting Individual Patient Differences in Generalization.

Purpose: Floating ball voice therapy (FBVT) is a voice-controlled virtual environment based on a common treatment component across multiple evidence-based therapies: improved vocal efficiency (target) via practicing voicing with modified resonance and airflow (ingredient). This study preliminarily tested FBVT's effects on outcomes and the potential for its novel variability metrics to predict individual patient generalization.

Method: Ten patients with nonphonotraumatic vocal hyperfunction (NPVH) practiced FBVT for 10 days.

Consistency of the Signature of Phonotraumatic Vocal Hyperfunction Across Different Ambulatory Voice Measures.

Purpose: Although different factors and voice measures have been associated with phonotraumatic vocal hyperfunction (PVH), it is unclear what percentage of individuals with PVH exhibit such differences during their daily lives. This study used a machine learning approach to quantify the consistency with which PVH manifests according to ambulatory voice measures. Analyses included acoustic parameters of phonation as well as temporal aspects of phonation and rest, with the goal of determining optimally consistent signatures of PVH.

Toward Generalizable Machine Learning Models in Speech, Language, and Hearing Sciences: Estimating Sample Size and Reducing Overfitting.

Purpose: Many studies using machine learning (ML) in speech, language, and hearing sciences rely upon cross-validations with single data splitting. This study's first purpose is to provide quantitative evidence that would incentivize researchers to instead use the more robust data splitting method of nested -fold cross-validation. The second purpose is to present methods and MATLAB code to perform power analysis for ML-based analysis during the design of a study.

Quantifying the Occupational Voice Use of Teachers.

Purpose: The teaching profession is a high-voice use occupation at elevated risk for developing voice disorders. Continued research on teachers' vocal demands is necessary to advocate for and establish vocal health programs. This study quantified ambulatory vocal dose measures for teachers during both on- and off-work periods, comparing their occupational voice use to that in other studies that have reported percent phonation ranging from 17% to 30%.

Detecting Mild Phonotrauma in Daily Life.

Objective: The aim of this study was to gain quantitative insights into the role of daily voice use associated with mild phonotrauma via the Daily Phonotrauma Index (DPI), a measure derived from neck-surface acceleration magnitude (NSAM) and difference between the first two harmonic magnitudes (H1 - H2).

Methods: An ambulatory voice monitor recorded weeklong voice use for 151 female patients with phonotraumatic vocal hyperfunction (PVH) and 181 female vocally healthy controls. Three laryngologists rated phonotrauma severity from each patient's laryngoscopy.

Acoustic-Aerodynamic Voice Outcome Ratios Identify Changes in Vocal Function Following Vocal Fold Medialization for Unilateral Vocal Fold Paralysis.

Purpose: This study aimed to determine whether ratio-based measures that combine acoustic (output) and aerodynamic (input) parameters detect postoperative change in vocal function following vocal fold medialization for unilateral vocal fold paralysis.

Method: Pre- and postoperative acoustic and aerodynamic measures were analyzed retrospectively from 149 patients who underwent vocal fold medialization for unilateral vocal fold paralysis. A 2 × 2 repeated-measures analysis of variance was conducted for each of four acoustic-aerodynamic ratios-traditional vocal efficiency (VE), sound pressure level to aerodynamic power (SPL/AP), SPL to average airflow (SPL/AFLOW), and SPL to subglottal pressure (SPL/Ps)-to investigate the main effects and interaction of treatment stage and loudness level (comfortable and loud).

Acoustic Voice and Speech Biomarkers of Treatment Status during Hospitalization for Acute Decompensated Heart Failure.

This study investigates acoustic voice and speech features as biomarkers for acute decompensated heart failure (ADHF), a serious escalation of heart failure symptoms including breathlessness and fatigue. ADHF-related systemic fluid accumulation in the lungs and laryngeal tissues is hypothesized to affect phonation and respiration for speech. A set of daily spoken recordings from 52 patients undergoing inpatient ADHF treatment was analyzed to identify voice and speech biomarkers for ADHF and to examine the trajectory of biomarkers during treatment.

Ambulatory Monitoring of Subglottal Pressure Estimated from Neck-Surface Vibration in Individuals with and without Voice Disorders.

The aerodynamic voice assessment of subglottal air pressure can discriminate between speakers with typical voices from patients with voice disorders, with further evidence validating subglottal pressure as a clinical outcome measure. Although estimating subglottal pressure during phonation is an important component of a standard voice assessment, current methods for estimating subglottal pressure rely on non-natural speech tasks in a clinical or laboratory setting. This study reports on the validation of a method for subglottal pressure estimation in individuals with and without voice disorders that can be translated to connected speech to enable the monitoring of vocal function and behavior in real-world settings.

Kalman Filter Implementation of Subglottal Impedance-Based Inverse Filtering to Estimate Glottal Airflow during Phonation.

Subglottal Impedance-Based Inverse Filtering (IBIF) allows for the continuous, non-invasive estimation of glottal airflow from a surface accelerometer placed over the anterior neck skin below the larynx. It has been shown to be advantageous for the ambulatory monitoring of vocal function, specifically in the use of high-order statistics to understand long-term vocal behavior. However, during long-term ambulatory recordings over several days, conditions may drift from the laboratory environment where the IBIF parameters were initially estimated due to sensor positioning, skin attachment, or temperature, among other factors.

Lombard Effect in Individuals With Nonphonotraumatic Vocal Hyperfunction: Impact on Acoustic, Aerodynamic, and Vocal Fold Vibratory Parameters.

Purpose: This exploratory study aims to investigate variations in voice production in the presence of background noise (Lombard effect) in individuals with nonphonotraumatic vocal hyperfunction (NPVH) and individuals with typical voices using acoustic, aerodynamic, and vocal fold vibratory measures of phonatory function.

Method: Nineteen participants with NPVH and 19 participants with typical voices produced simple vocal tasks in three sequential background conditions: baseline (in quiet), Lombard (in noise), and recovery (5 min after removing the noise). The Lombard condition consisted of speech-shaped noise at 80 dB SPL through audiometric headphones.

Clinical Utility of the Ratio of Sound Pressure Level to Subglottal Pressure in Patients Surgically Treated for Phonotraumatic Vocal Fold Lesions.

Purpose: This study aimed to determine whether a simplified, and potentially more stable, acoustic-aerodynamic voice outcome ratio (ratio of sound pressure level [SPL] to subglottal pressure) is comparable to a traditional vocal efficiency measure (ratio of acoustic power to the product of average subglottal pressure and average phonatory airflow) in terms of the ability to detect change in vocal function following surgical removal of bilateral phonotraumatic lesions.

Method: Pre- and postoperative acoustic and aerodynamic measures were analyzed retrospectively from 75 female patients who underwent surgical removal of bilateral phonotraumatic lesions. A 2 × 2 repeated-measures analysis of variance was conducted for each of three acoustic-aerodynamic voice outcome ratios-traditional vocal efficiency, an SPL-based ratio with both airflow and subglottal pressure, and a simplified SPL-based ratio with subglottal pressure only-to investigate the main effects of treatment stage (pre- and postsurgery), loudness condition (comfortable and loud), and their interaction.

Collision Pressure and Dissipated Power Dose in a Self-Oscillating Silicone Vocal Fold Model With a Posterior Glottal Opening.

Purpose: The goal of this study was to experimentally evaluate how compensating for the adverse acoustic effects of a posterior glottal opening (PGO) by increasing subglottal pressure and changing supraglottal compression, as have been associated with vocal hyperfunction, influences the risk of vocal fold (VF) trauma.

Method: A self-oscillating synthetic silicone model of the VFs with an airflow bypass that modeled a PGO was investigated in a hemilaryngeal flow facility. The influence of compensatory mechanisms on collision pressure and dissipated collision power was investigated for different PGO areas and supraglottal compression.

Daily Phonotrauma Index: An Objective Indicator of Large Differences in Self-Reported Vocal Status in the Daily Life of Females With Phonotraumatic Vocal Hyperfunction.

Purpose: The purpose of this study is to evaluate if the Daily Phonotrauma Index (DPI) can quantitatively discriminate large differences in overall vocal status in the daily life of patients with phonotraumatic vocal hyperfunction (PVH).

Method: For 1-4 weeks, 23 females with PVH wore an ambulatory voice monitor and answered three vocal status questions (i.e.

Clinical Cutoff Scores for Acoustic Indices of Vocal Hyperfunction That Combine Relative Fundamental Frequency and Cepstral Peak Prominence.

Purpose: This study examined the discriminative ability of acoustic indices of vocal hyperfunction combining smoothed cepstral peak prominence (CPPS) and relative fundamental frequency (RFF).

Method: Demographic, CPPS, and RFF parameters were entered into logistic regression models trained on two 1:1 case-control groups: individuals with and without nonphonotraumatic vocal hyperfunction (NPVH; = 360) and phonotraumatic vocal hyperfunction (PVH; = 240). Equations from the final models were used to predict group membership in two independent test sets ( = 100 each).

Framework for Indirect Spatial Calibration of the Horizontal Plane of Endoscopic Laryngeal Images.

Objective: Calibrated horizontal-plane measurements from laryngeal images could contribute significantly to refining evidence-based practice and developing patient-specific models and precision-medicine approaches. Laser-projection endoscopes can address the need for direct calibrated measures; however, these systems are not widely available. This study presents the framework for an alternative indirect horizontal-plane calibration approach.

Ambulatory Voice Biofeedback: Acquisition and Retention of Modified Daily Voice Use in Patients With Phonotraumatic Vocal Hyperfunction.

Purpose: Voice ambulatory biofeedback (VAB) has potential to improve carryover of therapeutic voice use into daily life. Previous work in vocally healthy participants demonstrated that motor learning inspired variations to VAB produced expected differences in acquisition and retention of modified daily voice use. This proof-of-concept study was designed to evaluate whether these VAB variations have the same desired effects on acquisition and retention in patients with phonotraumatic vocal hyperfunction (PVH).

Relationships Among Personality, Daily Speaking Voice Use, and Phonotrauma in Adult Female Singers.

Purpose: This study sought to determine whether personality traits related to extraversion and impulsivity are more strongly associated with singers with nodules compared to vocally healthy singers and to understand the relationship between personality and the types of daily speaking voice use.

Method: Weeklong ambulatory voice recordings and personality inventories were obtained for 47 female singers with nodules and 47 vocally healthy female singers. Paired tests investigated trait differences between groups.

Psychometric Analysis of an Ecological Vocal Effort Scale in Individuals With and Without Vocal Hyperfunction During Activities of Daily Living.

Objective The purpose of this study was to examine the psychometric properties of an ecological vocal effort scale linked to a voicing task. Method Thirty-eight patients with nodules, 18 patients with muscle tension dysphonia, and 45 vocally healthy control individuals participated in a week of ambulatory voice monitoring. A global vocal status question was asked hourly throughout the day.