Chayadevie Nanjundeswaran

Vocal Fatigue Index (VFI): Development and Validation

OBJECTIVE To develop a psychometrically sound self-report questionnaire, the Vocal Fatigue Index (VFI), to help identify individuals with vocal fatigue (VF) and characterize their complaints. STUDY DESIGN Descriptive research-scale development. METHODS Four laryngologists and six speech-language pathologists specialized in voice created a beta version of the VFI (version 1), an index of 21 statements they considered to reflect VF. Two hundred patients presenting to two different clinics completed the VFI-1. Two items from VFI-1 were excluded because of poor item-to-total correlations. The final VFI of 19 items (version 2), completed by 105 patients with voice complaints and 70 vocally healthy individuals, was assessed for its psychometric properties. RESULTS Test-retest reliability for the final VFI was generally strong, as was sensitivity and specificity using the classification table under logistic regression for correctly distinguishing individuals with and without VF. Moreover, factor analysis indicated that VF may be characterized by three factors: (1) factor 1, related to tiredness of voice and voice avoidance, (2) factor 2, related to physical discomfort associated with voicing, and (3) factor 3, related to improvement of symptoms with rest. CONCLUSION The VFI is a standardized tool that can identify individuals with probable VF with good reliability, validity, sensitivity, and specificity.

Preliminary Data on Prevention and Treatment of Voice Problems in Student Teachers

OBJECTIVES/HYPOTHESES To assess the utility of a targeted voice hygiene (VH) program compared to VH plus voice training intervention (VH+VT) for the prevention and treatment of voice problems in student teachers. STUDY DESIGN Prospective, randomized. METHODS Thirty-one student teachers with low (good) and high (poor) voice handicap index (VHI) scores in Pittsburgh and Hong Kong were randomly assigned to (1) a targeted, individually tailored VH program, (2) the VH program plus resonant VT (VH+VT), or (c) a control group. Participants assigned to intervention groups were monitored for their adherence to their programs for their first 4 weeks of student teaching. VHI data were collected again 4 weeks postintervention (both sites) and 8 weeks postintervention, following a no-contact washout period (Pittsburgh). RESULTS Descriptive data analysis indicated that across both sites, for initially healthy participants, the VH program was sufficient to prevent worsening of VHI scores that occurred in all control participants over the first 4-8 weeks of student teaching. The addition of VT did not consistently enhance protective benefits over VH alone. In contrast, for participants with initially poor VHI scores, the VH program failed to produce VHI benefits over the control condition. The addition of VT was required to optimize results for that cohort. CONCLUSIONS Preliminary data suggest that a minimalist, individually tailored VH program may be sufficient to prevent voice problems from teaching in healthy student teachers. However, for student teachers with existing voice problems, VT may be required to optimize results of intervention.

Autonomic and emotional responses of graduate student clinicians in speech–language pathology to stuttered speech

BACKGROUND Fluent speakers and people who stutter manifest alterations in autonomic and emotional responses as they view stuttered relative to fluent speech samples. These reactions are indicative of an aroused autonomic state and are hypothesized to be triggered by the abrupt breakdown in fluency exemplified in stuttered speech. Furthermore, these reactions are assumed to be the basis for the stereotypes held by different communicative partners towards people who stutter. AIMS To examine the autonomic and emotional reactions of graduate student clinicians in speech-language pathology as they viewed fluent and severe stuttered speech samples. METHODS & PROCEDURES Twenty-one female graduate student clinicians in speech-language pathology participated in this study. Each participant viewed four 30-s video samples (two fluent and two stuttered speech samples) while their autonomic responses (skin conductance response (SCR) and heart rate (HR)) were concurrently captured. Furthermore, emotional responses to stuttered and fluent speech samples were captured using the self-assessment manikin (SAM) and a rating scale with nine bipolar adjectives reflecting ones feelings. OUTCOMES & RESULTS An increase in SCR and deceleration in HR was observed as graduate clinicians viewed stuttered speech samples versus fluent speech samples and the differences were statistically significant. In addition, results from the self-rating scales showed that participants had negative feelings (e.g., emotionally aroused, unpleasant, embarrassed, uncomfortable, etc.) while viewing stuttered speech. CONCLUSIONS & IMPLICATIONS Findings suggest that graduate student clinicians in speech-language pathology demonstrated altered autonomic and emotional responses similar to those manifested by fluent and stuttered speakers as they viewed stuttered speech samples. Collectively, these findings support the contention that the inherent nature of stuttered speech triggers a visceral reaction in a listener, irrespective of their background and knowledge about the disorder.

The effect of static and dynamic visual gestures on stuttering inhibition.

The aim of the study was to evaluate the role of steady-state and dynamic visual gestures of vowels in stuttering inhibition. Eight adults who stuttered recited sentences from memory while watching video presentations of the following visual speech gestures: (a) a steady-state /u/, (b) dynamic production of /a-i-u/, (c) steady-state /u/ with an accompanying audible 1 kHz pure tone, and (d) dynamic production of /a-i-u/ with an accompanying audible 1 kHz pure tone. A 1 kHz pure tone and a no-external signal condition served as control conditions. Results revealed a significant main effect of auditory condition on stuttering frequency. Relative to the no-external signal condition, the combined visual plus pure tone conditions resulted in a statistically significant reduction in stuttering frequency. In addition, a significant difference in stuttering frequency was also observed when the visual plus pure tone conditions were compared to the visual only conditions. However, no significant differences were observed between the no-external signal condition and visual only conditions, or the no-external signal condition and pure tone condition. These findings are in contrast to previous findings demonstrated by similar vowel gestures presented via the auditory modality that resulted in high levels of stuttering inhibition. The differential role of sensory modalities in speech perception and production as well as their individual capacities to transfer gestural information for the purposes of stuttering inhibition is discussed.

Restructuring the Vocal Fatigue Index Using Mokken Scaling: Insights Into the Complex Nature of Vocal Fatigue

Vocal fatigue is a frequent symptom and a debilitating condition affecting individuals with voice disorders. In spite of the various attempts to define and quantify vocal fatigue, this complex trait has not been well understood. Mokken scaling was performed on the Vocal Fatigue Index (VFI) to develop a hierarchical understanding of the latent trait of vocal fatigue. Two hundred nine patients with voice disorders completed the VFI and provided the item responses necessary to complete the Mokken scaling. Results revealed a moderately strong Mokken scale and that the VFI presents a hierarchical structure to the underlying trait of vocal fatigue. Mokken scaling contributes to the ongoing investigation to the underlying construct of vocal fatigue and may provide additional information about specific complaints within the population of those with voice disorders.

Metabolic Mechanisms of Vocal Fatigue.

OBJECTIVE This study aimed to identify potential metabolic mechanisms including (1) neuromuscular inefficiency, (2) cardiovascular recovery deficits, or (3) both, in individuals with complaints of vocal fatigue. STUDY DESIGN Within- and between-subjects group design was used in this study. METHODS Three groups of women participated in the study, including (1) individuals with complaints of vocal fatigue; (2) vocally healthy sedentary individuals; and (3) vocally healthy, cardiovascularly conditioned individuals. Group assignment was based on results from the Vocal Fatigue Index, laryngeal examination, and self-report regarding exercise regimens. Metabolic profiles were obtained using gas exchange measures monitored during vocal task performance (reading) at two different loudness levels, and during recovery from reading. RESULTS Statistical analyses did not reveal reliable group differences in metabolic cost for or recovery from vocal tasks. However, descriptive review of oxygen uptake and recovery kinetics revealed patterns indicating reliance on differential energy resources for the vocal task in individuals with vocal fatigue compared with cardiovascularly trained, vocally healthy individuals in particular. Slow oxygen uptake kinetics at task onset was a characteristic of the vocal fatigue group, indicating a general reliance on anaerobic resources to meet the demands of the vocal task, pointing to possible neuromuscular inefficiency. Individuals with vocal fatigue also demonstrated an increase in oxygen consumption following vocal task compared with cardiovascularly trained individuals, suggesting possible cardiovascular recovery deficits. CONCLUSION This study provides initial data relevant to possible metabolic mechanisms of vocal fatigue and the potential relevance of aerobic conditioning in individuals with such fatigue.

Cross-Cultural Adaptation and Validation of the Vocal Fatigue Index into Persian

INTRODUCTION The aim of the present study was the cross-cultural adaptation and validation of the Vocal Fatigue Index (VFI) in Persian. METHODS The English version of the VFI was translated to Persian using the guidelines of International Quality of Life Assessment. Eighty participants with voice disorders and 50 healthy controls without any voice disorders completed the Persian version of the VFI. The 80 participants with voice disorders completed the VFI a second time a week from the initial completion to evaluate test-retest reliability. RESULTS The VFI measure demonstrated a strong internal consistency. Cronbach alpha coefficient was 0.95 for tiredness and avoidance of voice use, 0.86 for physical discomfort and 0.83 for improvement or lack thereof of symptoms with voice rest. VFI also showed a high test-retest reliability (r = 0.75-0.89). CONCLUSIONS The Persian version of the VFI is considered to be a valid and reliable questionnaire for identifying individuals with probable vocal fatigue. The VFI can be utilized in clinics across Iran in the assessment and treatment of individuals with vocal fatigue.