Relationship Between Tasked Vocal Effort Levels and Measures of Vocal Intensity

Isolated and combined effects of steam inhalation via the voiced high-frequency oscillation technique after a short vocal loading task in healthy female voices

OBJECTIVE

The first aim of the study, to determine the effects of a vocal loading task (VLT) involving reading a passage at a level of 80-85 dBA(30 cm) for 10 minute (min) on voice. The second aim is to identify the effects of three different therapeutic strategies performed immediately after the VLT on voice.

METHOD

The sample of the study included 32 normophonic female participants. The research procedure involved three different therapeutic strategies: sterile water nebulization, voiced oral high-frequency oscillation (VOHFO) and the combined application following three different vocal loading tasks performed for 10 min. The assessments were made using acoustic, electroglottographic, perceived vocal effort (Borg CR-10) measurement methods.

RESULTS

The 10 min VLT did not significantly affect the acoustic (except for fundamental frequency-Fo) or electroglottographic parameters of the habitual voice, while it led to an increased level of perceived vocal effort scores and Fo values. Perturbation and perceptual effort decreased after all three therapeutic interventions, but Fo remained higher than baseline; EGG-contact quotient (CQ) decreased after VOHFO-inclusive therapeutic interventions and perceptual effort level did not decrease after nebulization but decreased after VOHFO-inclusive interventions.

CONCLUSION

The 10 min VLT, which was of a short duration, led to an increased level of perceived vocal effort scores and Fo values. In addition, all therapeutic interventions were found to decrease perturbation and perceived vocal effort. However, according to the EGG-CQ data, the addition of therapeutic factors such as VOHFO to superficial vocal fold hydration procedures may further enhance their beneficial effects on the voice.

The Effect of Laryngeal Dehydration and Nebulized Osmotic Agents on the Voice

OBJECTIVE

This study investigates the effects of dehydration induced by dry air breathing and the nebulization of various osmotic agents on vocal parameters, including perceptual, acoustic, and electroglottographic measures.

METHODS

Thirty normophonic females (age x̅ = 26, SD = 1.67) participated over three consecutive days. On the first day, the baseline data were meticulously collected before the participants underwent a 22-minute session of transoral dry air breathing. Immediately after this desiccation protocol, measurements were taken to establish the initial effects. Subsequently, one of three osmotic agents was randomly selected for each participant. These agents included hypotonic distilled water, 0.9% isotonic saline, and 3% hypertonic saline. Each participant then underwent a 10-minute nebulization session with 5 mL of the assigned osmotic agent. The process was repeated on the second and third days. Each day, the participants again experienced the 22-minute transoral dry air breathing session. The evaluations were performed by Borg CR-10 (perceived vocal effort), electroglottography (EGG), voice onset time (VOT), nasalance score (NS), and cepstral peak prominence analyses with CAPE-V sentences (s).

RESULTS

No statistically significant differences were found in the EGG parameters between the preliminary recordings, post transoral medical-grade dry air protocol, and after each of task-hypotonic, task-isotonic, and task-hypertonic. Following the transoral medical-grade dry air protocol, both /s1/-CPP and /s5/-CPP values decreased compared with the preliminary recordings. Only /s1/-CPP values increased after the 0.9% isotonic saline nebulization. NS from preliminary measurements was higher for both oronasal and nasal texts compared with scores after the dry air protocol and nebulization. Voiceless plosive VOT values decreased solely after the 0.9% isotonic saline nebulization. Participants' Borg CR-10 scores increased after transoral medical-grade dry air protocol and decreased after nebulization with distilled water and 0.9% isotonic saline.

CONCLUSIONS

Isotonic saline and distilled water nebulization protocols demonstrated a trend toward mitigating the adverse effects of the transoral medical-grade dry air inhalation protocol on vocal parameters.

Effects of a Short-Term Vocal Loading Task and Different Restoration Strategies on Voice

OBJECTIVE

The purpose of this study is to examine the effects of a short-term (30 minutes) vocal loading task (VLT) on the objective and subjective parameters of voice and determine the restorative strategies of three different vocal exercises performed after the VLT.

METHODS

The sample of the study included 30 normophonic women. The protocols that were applied in the study were carried out on three consecutive days. In each protocol, right after the VLT based on 30 minutes of phonation at 80-85 dBA30 cm, a randomly selected strategy from among the three different therapeutic strategies was performed for 10 minutes. The therapeutic strategies consisted of the water resistance therapy (tube submerged depth 3-cm) (WRT protocol), the voiced oral high-frequency oscillation (VOHFO) technique performed using the Acapella Duet (Smith Medical, USA) (VOHFO protocol), and the semi-occluded nasal tract exercise (SONTE) (SONTE protocol). The analyses were conducted based on acoustic, electroglottographic, and perceived vocal exertion (Borg CR-100) measurements made at different time points.

RESULTS

After the VLT, increased fundamental frequency (Fo) and cepstral peak prominence (CPP) values, and decreased electroglottography (EGG)-contact quotient (CQ) and nasalance score values were observed. In comparison to the values measured before the performance of the exercises, during all three exercises, EGG-CQ values decreased, and EGG-average (Avg.) jitter values increased. Among the three included exercises, the lowest Borg CR-100 scores were obtained after the SONTE protocol. Only the EGG-CQ values obtained after the SONTE and VOHFO protocols were lower than those obtained after the VLT.

CONCLUSIONS

The short-term (30 minutes) VLT (80-85 dBA30 cm) performed in this study led to differences in the subjective and objective parameters that were measured, and it was considered to be an effective VLT. All three exercises that were used immediately after the VLT as restoration strategies were observed to be effective in reducing perceptual vocal effort scores, and similar vocal fold movement patterns were observed during the exercises according to the EGG results. According to the increased acoustic-CPP and reduced EGG-CQ and EGG-Avg. jitter parameter values after the exercises, the SONTE and VOHFO protocols were more successful than the WRT protocol in stabilising the negative effects of vocal loading.

Self-Perception of Vocal Effort in Response to Modeled Communication Demands

OBJECTIVES

The optimization of vocal effort given a response to a voice demand is a common clinical and vocal performance goal. Increases in vocal effort are often in response to communication limitations from both the interlocutors and the communication environment. This study investigates the relationship between vocal effort and vocal demands from changes and limitations imposed by the communication environment.

METHODS

Thirty-seven participants rated their vocal effort associated with a map description task in a range of communication demands. These demands included communication distance (from 1 m to 4 m), loudness goal (54 dB-66 dB), and excess background noise (53 dBA-71 dBA). The vocal effort ratings were compared across the different types and extents of vocal demand conditions.

RESULTS

As would be expected, there were significant increases in vocal effort levels from the control condition to the extremes of the distance and loudness goal vocal demands. Each increase in background noise resulted in distinct increases in vocal effort level. Participants were able to use the vocal effort scale to efficiently quantify expected increases in vocal demands.

CONCLUSIONS

Increases of vocal effort level accompany increases to vocal demands that exceed the habitual or expected communication. While voice training and vocal therapy are essential for reducing internal vocal demands, clients with a goal to reduce vocal effort should also consider external vocal demands such as communication distance and background noise.

Empatica E4 Assessment of Child Physiological Measures of Listening Effort During Remote and In-Person Communication

PURPOSE

Telepractice is a growing service model that delivers aural rehabilitation to deaf and hard-of hearing children via telecommunications technology. Despite known benefits of telepractice, this delivery approach may increase patients' listening effort (LE) characterized as an allocation of cognitive resources toward an auditory task. The study tested techniques for collecting physiological measures of LE in normal-hearing (NH) children during remote (referred to as tele-) and in-person communication using the wearable Empatica E4 wristband.

METHOD

Participants were 10 children (age range: 9-12 years old) who came to two tele- and two in-person weekly sessions, order counterbalanced. During each session, the children heard a short passage read by the clinical provider, completed an auditory passage comprehension task, and self-rated their effort as a part of the larger study. Measures of electrodermal activity and blood volume pulse amplitude were collected from the child E4 wristband.

RESULTS

No differences in child subjective, physiological measures of LE or passage comprehension scores were found between in-person sessions and telesessions. However, an effect of treatment duration on subjective and physiological measures of LE was identified. Children self-reported a significant increase in LE over time. However, their physiological measures demonstrated a trend indicating a decrease in LE. A significant association between subjective measures and the passage comprehension task was found suggesting that those children who reported more effort demonstrated a higher proportion of correct responses.

CONCLUSIONS

The study demonstrated the feasibility of collection of physiological measures of LE in NH children during remote and in-person communication using the E4 wristband. The results suggest that measures of LE are multidimensional and may reflect different sources of, or cognitive responses to, increased listening demand.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.27122064.

Vocal Fold Vibratory Dose and Perceived Exertion Responses to the Fluid Interval Test for Voice (FIT-V): A Novel Vocal Loading Task Platform

INTRODUCTION

Vocal loading tasks are often used to study how specific variables influence downstream vocal effort or fatigue. The current study introduces a novel vocal loading task, the Fluid Interval Test for Voice (FIT-V) that combines laryngeal diadochokinesis, intervallic rest and exercise, and fluid back pressure. To assess the differences between this novel task and existing vocal loading tasks, we measured vocal fold vibratory dose and perceived phonatory exertion across three 30-minute task conditions: a control loud oral reading task (LOR), a back pressure-resisted Fluid Interval Test for Voice (FIT-V5), and an unresisted Fluid Interval Test for Voice (FIT-V0).

METHODS

Following a training session, 30 participants completed the three tasks (LOR, FIT-V0, and FIT-V5) in counterbalanced order on different days. Vocal fold cycle (Aim 1A) and distance doses (Aim 1B) were collected continuously using a dosimeter. The overall perceived phonatory exertion (Aim 2A) was rated once per minute, while anatomically localized cognitive, laryngeal, thoracic, abdominal, and articulatory exertion (Aim 2B) were rated once at the end of each task. Statistical analyses examined the effects of task and task× time interactions on the dependent variables.

RESULTS

The FIT-V0 and FIT-V5 tasks imposed smaller vocal fold cycle doses (P < 0.001; Aim 1A) and distance doses (P < 0.001; Aim 1B) than the LOR task while eliciting comparable or greater magnitudes of overall perceived phonatory exertion (P = 0.003; Aim 2A). However, anatomically localized perceived exertion was greater in the abdomen and thorax (P < 0.05) and lesser in the anterior neck (P < 0.05) in the two FIT-V tasks relative to the LOR task (Aim 2B). Absolute forced vital capacity was a significant predictor of most forms of anatomically localized perceived exertion.

DISCUSSION

The unresisted FIT-V0 and the back pressure-resisted FIT-V5 tasks yielded similar profiles of overall perceived phonatory exertion, despite vocal fold vibratory doses roughly half that of the LOR task. However, the anatomically localized perceived exertion data underscored subtle across-task differences not apparent in the overall ratings, suggesting potentially distinct physiological and perceptual niches for the three task protocols.

Adult Normative Data for the OMNI-Vocal Effort Scale (VES)

PURPOSE

To establish normative values for the OMNI-Vocal Effort Scale (VES) in healthy adults without voice complaints. Secondary objective is to determine if there are differences in perceived vocal effort across age groups and between sexes.

STUDY DESIGN

Prospective data collection across groups.

METHOD

A nine-item survey was administered by speech-language pathologists with specialization in voice to consenting adults 18 years or older. Participants underwent an auditory perceptual evaluation of voice and answered questions regarding age, history of voice problems, history of voice surgery, smoking history and hearing loss. Participants were instructed to rate their perceived vocal effort in conversational speech using the OMNI-VES. Multivariant analysis was conducted.

RESULTS

Two hundred and fifty-one participants were recruited. The majority of adults without voice complaints reported that producing conversational voice was within the "extremely easy" to "easy" range, 0-3 (92.4%).

CONCLUSIONS

This study provides preliminary data for perceived vocal effort. The OMNI-VES may be a useful tool in understanding changes in perceived vocal effort as a result of treatment for voice disorders. Further normative data are needed between sexes, across the gender spectrum, and older adult populations. Future directions include examining the magnitude of difference between numeric values on the scale and use of the scale with other dysphonic populations.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:3726-3731, 2024.

Effects of Back Pressure on the Feasibility and Tolerability of Laryngeal Diadochokinetic Exercise: A Pilot Study

BACKGROUND

The term vocal demand response refers to how speakers meet vocal demands. Vocal loading tasks with predetermined demand parameters (duration, pitch, loudness, etc) have been used in research to study the vocal demand response; these have historically consisted of loud sustained vowel and loud speech tasks. Tasks founded on laryngeal diadochokinesis (LDDK) may be viable alternatives, especially if demand parameters such as exercise-rest ratio and fluid back pressure are concurrently modulated.

OBJECTIVES

To explore the effects of four fluid back pressure conditions (0, 5, 10, and 15 cm H2O) on several measures of subjective participant experience, feasibility, and tolerability during intervallic laryngeal diadochokinetic exercise.

METHODS

Participants (n = 12) completed 15-minute trials of LDDK in 30-second rest and exercise intervals against four counterbalanced back pressure conditions: 0, 5, 10, and 15 cm H2O. The effects of back pressure on (1) ratings of perceived vocal exertion, (2) prevalence of adverse effects such as shortness of breath or lightheadedness, (3) subjective difficulty of sustaining LDDK, (4) number of exercise intervals completed, (5) rankings of participant-preferred back pressure levels, and (6) expert ratings of auditory-perceptual diadochokinetic strength were assessed descriptively.

RESULTS

Perceived vocal exertion, lightheadedness, and subjective laryngeal diadochokinetic difficulty increased as back pressure increased. Number of intervals completed, auditory-perceptual diadochokinetic strength, and participant rankings of back pressure conditions, by contrast, decreased as back pressure increased. 0 and 5 cm H2O were the most preferred back pressure conditions overall.

DISCUSSION

Fluid back pressure was feasible and broadly tolerated during 15-minute trials of vocal exercise. However, the transition from 5 → 10 cm H2O appeared to represent an inflection point in our results: a minority of participants did not tolerate exercise at 10 cm H2O, becoming a majority at 15 cm H2O. We conclude that fluid back pressure should be restricted to values between 0 and 10 cm H2O during LDDK.

A Semiautomated Protocol Towards Quantifying Vocal Effort in Relation to Vocal Performance During a Vocal Loading Task

To increase the reliability and comparability of vocal loading studies, this paper proposes the use of a standardized approach with experiments that are [1] grounded on consistent definitions of terms related to vocal fatigue (vocal effort, vocal demand, and vocal demand response), and [2] designed to reduce uncertainty and increase repeatability. In the approach, a semi-automated vocal loading task that also increases efficiencies in collecting and preparing vocal samples for analysis was used to answer the following research question: To what extent is vocal effort and vocal demand response sensitive to changes in vocal demands (ie, noise only, noise plus duration)? Results indicate that the proposed protocol design consistently induced change in both vocal effort and vocal demand response, indicating vocal fatigue. The efficacy of future vocal loading studies would be improved by adopting a more consistent methodology for quantifying vocal fatigue, thus increasing interstudy comparability of results and conclusions.

Within-talker and within-session stability of acoustic characteristics of conversational and clear speaking stylesa)

In speech production research, talkers often perform a speech task several times per recording session with different speaking styles or in different environments. For example, Lombard speech studies typically have talkers speak in several different noise conditions. However, it is unknown to what degree simple repetition of a speech task affects speech acoustic characteristics or whether repetition effects might offset or exaggerate effects of speaking style or environment. The present study assessed speech acoustic changes over four within-session repetitions of a speech production taskset performed with two speaking styles recorded in separate sessions: conversational and clear speech. In each style, ten talkers performed a set of three speech tasks four times. Speaking rate, median fundamental frequency, fundamental frequency range, and mid-frequency spectral energy for read sentences were measured and compared across test blocks both within-session and between the two styles. Results indicate that statistically significant changes can occur from one repetition of a speech task to the next, even with a brief practice set and especially in the conversational style. While these changes were smaller than speaking style differences, these findings support using a complete speech set for training while talkers acclimate to the task and to the laboratory environment.

Quantifying Vocal Repertoire Tessituras Through Real-Time Measures

INTRODUCTION

Voice teachers use anecdotal evidence and experience in determining the appropriateness of repertoire for each student's development. Tessitura is important in that determination, but until recently a straightforward, repeatable, and quantifiable method for determining tessitura has not existed. However, technology exists to provide the means to estimate the tessituras of standard vocal repertoire by measuring sung pitch (fundamental frequency) and vocal dose (amount of phonation) in real-time performance.

PURPOSE

The purpose of this study was to examine the combined use of tessituragrams, Voice Range Profiles (VRPs), a singer's self-perception of a performance, and expert listeners perception of a performance towards the goal of a more systematic way of selecting appropriate voice repertoire for singers. The following research questions guided this investigation: 1) How do Performance Range Profiles (PRPs, performance-based tessituragrams computed from neck skin surface vibration during singing), compare to score-based tessituragrams of the same selection in the same key? 2) How do PRPs of the same vocal score compare when performed in three different keys? 3) How do singer VRPs compare with PRPs of three performances of a score, each sung in a different key? and 4) How do singer and expert panel perceptions of the selection's "fit" in three different keys compare with the alignment of each singer's VRP to their PRPs? Four female singers and five expert voice pedagogues were enlisted to address these questions.

RESULTS

The distribution (histogram) of the score-based tessituragram closely matched the distribution of performance-based tessituragrams (PRP), suggesting that score-based tessituragrams have promise in accurately reflecting the performance-based tessitura of a musical vocal work. Acquired data revealed relationships of practical importance between score-derived tessituragrams, PRPs, acquired VRPs, and singer perceptions of ease in singing. These data suggest that score-based tessituragrams aligned with singer VRPs show promise in repertoire selection. However, there was only a minor relationship between expert panel perceptions of ease in singing and the acquired PRPs or singer perceptions of ease. Creation of a score-based tessituragram database could be combined with singer VRPs to assist in appropriate repertoire selection.

Effects of warm-up exercises on self-assessed vocal effort

PURPOSE

An elevated sense of vocal effort due to increased vocal demand is frequently reported by patients with voice disorders. However, effects of vocal warm-up on self-assessed vocal effort have not been thoroughly examined. A recently developed version of the Borg CR-10 Scale facilitates vocal effort assessments, following different vocal warm-up tasks.

METHODS

Effects of a short (5 min) vocal warm-up on self-assessed vocal effort was evaluated using the Borg CR-10. Twenty-six vocally healthy participants (13F, 13M, mean age 22.6), in two randomised groups, underwent sessions of either reading aloud or semi-occluded vocal tract exercises (SOVTE). Vocal effort was evaluated at four times: pre to post vocal warm-up and two silence periods. Non-parametric analyses for repeated measures and calculations for within-subject standard deviation were applied in group comparisons.

RESULTS

Following vocal warm-up, vocal effort ratings were increased to a statistically significant degree in both intervention groups compared to baseline ratings. After a 5-min rest in silence following completion of the vocal warm-up, vocal effort ratings returned to baseline levels in both groups. The drop in ratings immediately post warm-up compared to 5 min later was statistically significant for the SOVTE group.

CONCLUSIONS

Five minutes of vocal warm-up caused increased self-perceived vocal effort in vocally healthy individuals. The increased sense of effort dissipated faster following warm-up for the SOVTE group. When using the Borg CR-10 scale to track vocal effort, it may be beneficial to apply experience-based anchors.

Association Between Bilingualism, Vocal Effort, and Background Noise With Voice Fundamental Frequency and LTAS Among Spanish-English Bilingual Teachers

BACKGROUND

As the world becomes increasingly interconnected, the demand for bilingual teachers has grown exponentially. However, the unique combination of being a bilingual occupational voice user establishes challenges that warrant careful examination.

OBJECTIVE

To investigate the association between bilingualism, vocal effort, and background noise with fundamental frequency and long-term spectrum average among Spanish-English bilingual teachers.

METHODS

Exploratory cross-sectional correlational study with the participation of eight Spanish-English proficient bilingual teachers (native Spanish speakers) who were teaching online classes during the quarantines established to mitigate the propagation of COVID-19. Participants were asked to read two standardized texts (one in English and one in Spanish) under two background noise conditions (with and without background white noise).

RESULTS

There was a significant interaction between language and vocal effort considering that the association of vocal effort with fo was different for Spanish and English. There was also a significant main effect of background noise on fo. There were significant differences in voice spectral characteristics between productions in Spanish and English and between productions with and without background noise. The alpha ratio was significantly higher in productions in English and with background noise compared with productions in Spanish without background noise. The mid to high spectral energy ratio (1-5 K/5-8 K) was significantly lower in productions in English and with higher perceived vocal effort compared with productions in Spanish and with lower scores on the Borg Scale.

CONCLUSION

Our findings introduce a need perspective by emphasizing the impact of speaking a second language on the work-relatedness of voice disorders among teachers. These findings stress the necessity to factor in language and environmental conditions for the comprehensive evaluation and management of work-related voice disorders.

Systematic Review of Literature on Vocal Demand Response: Understanding Physiology, Measurements, and Associated Factors

PURPOSE

Considering the conceptual migration from vocal load and vocal loading to vocal demand and vocal demand response, this review of literature aimed to identify physiological explanations, reported measurements, and associated factors (vocal demands) reported in the literature when considering the phonatory response to a vocal demand.

METHODS

A systematic review of literature, following the PRISMA Statement, was conducted using Web of Science, PubMed, Scopus, and ScienceDirect. Data were analyzed and presented in two parts. First, a bibliometric analysis, co-occurrence analysis, and content analysis were performed. Three criteria that got article inclusion were defined: (1) written in English, Spanish, and Portuguese; (2) published between 2009 and 2021; and (3) focused on vocal load and loading, vocal demand response, and voice assessment parameters. A total of 54 publications met the criteria and were included in this review. The second part included a conceptual framework based on the content analysis of three aspects of vocal demand response: (1) physiological explanations, (2) reported measurements, and (3) vocal demands.

RESULTS AND CONCLUSION

As would be expected since vocal demand response is a relatively new term and not yet commonly used in literature when discussing way that the speakers respond to communicative scenarios, most of the studies reviewed (both historical and recent) still use the term of vocal load and vocal loading. Although there is a broad variety of literature discussing a wide range of vocal demands and voice parameters used to characterize the vocal demand response, results show that there is consistency across the studies. While vocal demand response is unique and intrinsic to the talker, associated factors that contribute to this response include both internal talker and external talker factors. Internal factors include muscle stiffness, viscosity in the phonatory system, vocal fold tissue damage, elevated sound pressure levels during occupational voice demands, extended periods of voice use, suboptimal body posture, difficulties in breathing technique, and sleep disturbances. Associated external factors include the working environment (noise, acoustics, temperature, humidity). In conclusion, although vocal demand response is intrinsic to the speaker, the speaker's response is affected by external vocal demands. However, due to the wide methods to evaluate vocal demand response, it has been difficult to establish its contribution to voice disorders in the general population and, specifically, among occupational voice users. This literature review identified commonly reported parameters and factors that may help clinicians and researchers define vocal demand response.