Stroboscopy as a research instrument: development of a perceptual evaluation tool.

Laryngeal stroboscopy is arguably the most important clinical tool for the evaluation and treatment of patients with voice disorders. Unfortunately, at present, laryngeal stroboscopy is strictly a clinical tool and has no definitive use in the area of voice research. The limitation with laryngeal stroboscopy is the subjective nature of the interpretation of the video examination. A video stroboscopy research tool was developed using 10 stroboscopic parameters selected from the literature and clinical practice. The stroboscopy research tool was validated with the results of 18 reviewers using the instrument to rate 21 unique "cases" and 6 repeated "cases." The results of this video perceptual analysis study identified which parameters were the most robust and reliable across a wide range of reviewers and validated power analysis curves for future similar research. Furthermore, findings from this study revealed that a greater than 80% intra-rater reliability is the preferred method for the selection of a valid and reliable reviewer. Future research using this instrument will most likely increase the reliability and utility of the instrument with the use of prestudy reviewer training and/or the use of video examples to serve as anchors or external references.