Different Vibratory Conditions Elicit Different Structural and Biological Vocal Fold Changes in an In-Vivo Rabbit Model of Phonation.

The study used rabbits, not humans, and the two vibration patterns were not meant to represent human phonatory behavior. Only ten rabbits were studied, with three in each phonation group, so the findings are preliminary. The paper does not describe random allocation or blinding of tissue assessment. The contact and non-contact conditions differed in subglottic pressure and fundamental frequency, so the paper does not isolate vocal fold contact alone as the cause of tissue change. Formalin fixation and tissue processing may have shrunk tissue and could affect lamina propria depth. Tissue was collected immediately after 120 minutes, so later inflammatory cell infiltration may not have appeared. No gene expression or molecular pathway analyses were performed. No human voice therapy was tested, so clinical effects cannot be inferred.

The authors declared no conflicts of interest. The paper does not list a funding source.

Do not conclude that changing a patient's voice to reduce vocal fold contact will prevent lesions. The rabbits were not given therapy, the two vibration patterns were artificial and not necessarily representative of human phonation, and the study only showed tissue differences after induced phonation.