Clinical Efficacy of Synchronized Voice Playback in Evaluation of Dysphonia Using Digital Kymography

Abstract Background and Objectives High-speed videolaryngoscopy (HSV) is the most effective tool for visualizing vocal fold vibrations, offering superior image quality compared to laryngeal videostroboscopy (LVS). Digital kymography (DKG), derived from HSV, allows objective analysis of vibratory patterns, but lacks audio feedback, limiting its diagnostic utility. In contrast, LVS enables simultaneous audio-visual feedback, aiding in the diagnosis of functional voice disorders. To address this limitation, we developed an automated DKG system with synchronized voice playback and evaluated its diagnostic value. Subjects and Method We enrolled 102 patients with various voice disorders, including muscle tension dysphonia (n=16), spasmodic dysphonia (n=15), vocal tremor (n=14), vocal fold palsy (n=12), presbyphonia (n=12), and others. We compared diagnostic accuracy among three conditions: conventional DKG, DKG with non-synchronized voice playback, and DKG with synchronized voice playback. Two otolaryngologists and one speech-language pathologist assessed intra- and inter-rater reliability. Results Diagnostic accuracy was highest for DKG with synchronized voice playback (76.1%), compared to non-synchronized voice playback (58.1%) and conventional DKG (41.5%). The synchronized system showed significantly improved accuracy and reliability. Conclusion This is the first study to validate automated DKG with synchronized voice feedback. It presents a promising tool for diagnosing voice disorders, complementing HSV by incorporating auditory cues. Further clinical validation is needed. Key words : High-speed imaging ㆍ Vocal cords ㆍ Voice disorders