Objectives: This study aims to investigate the effects of voice disorders on changes in stress among people with damaged larynxes. To accomplish this, physiological changes and reductions in the stress of Sprague-Dawley rats whose larynx had been damaged were investigated after the laboratory animals were administered kudzu leaf extracts with sedative effects. Methods: In the experiment, a total of 24 rats were divided into four groups of six rats, including the normal group, control group, experimental group 1, and experimental group 2. After orally administering to the subjects a predetermined amount of the extract at a specific time (once per day over five weeks), changes in physiological functions, internal organ weight, cortisol, estrogen, and progesterone in the subjects were examined, and an immunological test was conducted on their brain tissues. Results: Statistical significance was seen in the experimental group as opposed to the control group and the results were similar to those of the normal group. Conclusions: In consideration of these results, it is deemed that there are severe effects on stress due to voice disorders and that the administration of kudzu leaf extracts results in improvement in stress.