Detecting Bifurcations in Voice Signals

Abstract

The lamina propria of the vocal folds is important in voice production. Understanding of the normal components of this layer and their distribution may further understanding of pathological processes. An evaluation of the distribution and ratio of fibroblasts and macrophages, the main cell types found in the lamina propria, and myofibroblasts, a repair cell, is reported. Twenty two normal human vocal folds were obtained from II male and 11 female patients. Using vimentin, CD68, and muscle specific actin stains, image analysis was used to determine the number and distribution of the three cell types in the lamina propria.Three distinct areas of different cellular activity, based on cell type and distribution are identified: The first area comprises the first twenty percent of the lamina propria, the second region is found in the middle sixty percent, and the last twenty percent of the lamina propria represents the third distinct area. We found that the number of fibroblasts is higher in superficial and deep layers of the lamina with a decrease in total cell number in the middle layer. The macrophages were found almost exclusively in the first twenty percent of the lamina and the distribution of myofibroblasts was greater in the first forty percent of the lamina. No significant gender difference was noted.These results indicate that most people (86% of our sample) with assumed normal vocal folds have reparative processes (based on the presence of myofibroblasts). In addition, some people (36% of our sample) have macrophage infiltration. The finding of three areas of different cellular activity may be useful in determining where the superficial, middle, and deep layers are located in the lamina propria and the location of associated pathological processes.

Relating pain intensity of newborns to onset of nonlinear phenomena in cry recordings

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Japanese macaque phonatory physiology

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