Recommended Protocols for Instrumental Assessment of Voice: American Speech-Language-Hearing Association Expert Panel to Develop a Protocol for Instrumental Assessment of Vocal Function.

Purpose: The aim of this study was to recommend protocols for instrumental assessment of voice production in the areas of laryngeal endoscopic imaging, acoustic analyses, and aerodynamic procedures, which will (a) improve the evidence for voice assessment measures, (b) enable valid comparisons of assessment results within and across clients and facilities, and (c) facilitate the evaluation of treatment efficacy. Method: Existing evidence was combined with expert consensus in areas with a lack of evidence. In addition, a survey of clinicians and a peer review of an initial version of the protocol via VoiceServe and the American Speech-Language-Hearing Association's Special Interest Group 3 (Voice and Voice Disorders) Community were used to create the recommendations for the final protocols. Results: The protocols include recommendations regarding technical specifications for data acquisition, voice and speech tasks, analysis methods, and reporting of results for instrumental evaluation of voice production in the areas of laryngeal endoscopic imaging, acoustics, and aerodynamics. Conclusion: The recommended protocols for instrumental assessment of voice using laryngeal endoscopic imaging, acoustic, and aerodynamic methods will enable clinicians and researchers to collect a uniform set of valid and reliable measures that can be compared across assessments, clients, and facilities.

Utility of Laryngeal High-speed Videoendoscopy in Clinical Voice Assessment.

OBJECTIVE: This study aimed to assess the utility of laryngeal high-speed videoendoscopy (HSV) as a clinical tool. DESIGN: This is a prospective study of 151 patients. METHODS: A total of 151 adult patients (52 male, 99 female) underwent both videoendoscopy with stroboscopy (videostroboscopy) and HSV examination as part of a routine clinical voice assessment. At the time of the examination, ratings for videostroboscopy were reported in the clinical report. Next, the clinicians reviewed the HSV examination and indicated the changes in ratings of HSV relative to videostroboscopy. Finally, the clinical reports were reviewed by a clinician not involved in data collection or clinical care of the patients and noted differences between videostroboscopy and HSV clinical ratings, and resulting diagnoses were identified and grouped. RESULTS: Ratings of all vibratory features showed change between videostroboscopy and HSV. Mucosal wave and amplitude of vibration showed the largest percentage change, respectively, in 74% and 53% of the reports. They were followed by the features of glottal closure (36%), phase closure (32%), glottal edge (25%), and phase symmetry (21%). Ratings of supraglottic compression and vocal fold vertical level showed the least change between videostroboscopy and HSV. Changes in initial diagnosis owing to the inclusion of HSV were indicated in 7% of the cases. CONCLUSIONS: HSV may be an important laryngeal imaging technique for functional assessment of the pathophysiology of certain voice disorders. HSV could enable important refinements in the diagnosis and management of vocal fold pathology.

Assessment of Vibratory Characteristics in Children Following Airway Reconstruction Using Flexible and Rigid Endoscopy and Stroboscopy.

IMPORTANCE: Up to half of children have substantial dysphonia after airway reconstruction. Visual assessment of vocal function is valuable. Feasibility of flexible and rigid endoscopy has been reported; however, the clinical utility of stroboscopy has not been examined. Rating of vibratory characteristics, such as mucosal wave and amplitude of vibration, is essential for the development of interventions to improve voice outcomes. OBJECTIVE: To examine (1) clinicians' ratings of anatomical and physiological features in children following airway reconstruction on initial voice evaluation using videolaryngostroboscopy and (2) the relationship of age to the type of endoscopy used. DESIGN, SETTING, AND PARTICIPANTS: Retrospective medical record review of 32 patients aged 3 to 21 years evaluated for post­airway reconstruction dysphonia between July 2011 and July 2012 at a quaternary care children's hospital. INTERVENTIONS: Clinical voice evaluation protocol including rigid and/or flexible endoscopy with stroboscopy. MAIN OUTCOMES AND MEASURES: Demographic and voice quality characteristics were collected. The ability to complete endoscopy and ratings of anatomical and/or physiological features were assessed by a consensus of 4 clinicians. A t test was used to determine whether age was a significant factor in successful completion of videolaryngostroboscopy. RESULTS: Of 31 children who underwent flexible videolaryngostroboscopy, 22 (71%) examinations were completed with a distal chip endoscope and 9 (29%) with a fiberoptic. Significant differences were found in age between children who completed the distal chip vs. fiberoptic examination (mean [SD], 7.3 [2.7] vs. 5.5 [6.2] years; P = .05). Rigid endoscopy was attempted for 14 (44%) of 32 patients; 9 examinations (64%) were successful. Significant differences were found in age between patients for whom a rigid endoscopy could be successfully completed vs. those for whom it was not (mean [SD], 12.9 [3.4] vs. 6.2 [2.1] years; P < .001). Eighteen (56%) were glottic phonators, 8 (25%) supraglottic, and 6 (19%) aphonic. Vibratory characteristics were visible in 10 of 37 examinations (27%); 6 (16%) had ratable characteristics. CONCLUSIONS AND RELEVANCE: Endoscopy can be successfully completed in most children who have undergone airway reconstruction, most often using a distal chip endoscope.We found that vibratory characteristics were often not assessed adequately using videolaryngostroboscopy. Further work identifying imaging modalities that better display vibratory characteristics, such as high-speed videoendoscopy, may provide new insight into vocal function and lead to a more thorough evaluation.

Experimental Investigation on Minimum Frame Rate Requirements of High-Speed Videoendoscopy for Clinical Voice Assessment.

This study investigated the impact of high-speed videoendoscopy (HSV) frame rates on the assessment of nine clinically-relevant vocal-fold vibratory features. Fourteen adult patients with voice disorder and 14 adult normal controls were recorded using monochromatic rigid HSV at a rate of 16000 frames per second (fps) and spatial resolution of 639×639 pixels. The 16000-fps data were downsampled to 16 other rate denominations. Using paired comparisons design, nine common clinical vibratory features were visually compared between the downsampled and the original images. Three raters reported the thresholds at which: (1) a detectable difference between the two videos was first noticed, and (2) differences between the two videos would result in a change of clinical rating. Results indicated that glottal edge, mucosal wave magnitude and extent, aperiodicity, contact and loss of contact of the vocal folds were the vibratory features most sensitive to frame rate. Of these vibratory features, the glottal edge was selected for further analysis, due to its higher rating reliability, universal prevalence and consistent definition. Rates of 8000 fps were found to be free from visually-perceivable feature degradation, and for rates of 5333 fps, degradation was minimal. For rates of 4000 fps and higher, clinical assessments of glottal edge were not affected. Rates of 2000 fps changed the clinical ratings in over 16% of the samples, which could lead to inaccurate functional assessment.