In Part 1 of his presentation, Dr. Johnson reviewed typical changes in the voice that relate to aging. His research group does MRI work and imaging studies in both humans and rodents. An increase in the number of older adults has helped to shift research into how to improve the quality of life among this group. He likes the following definition of aging: "It is a time-independent series of cumulative, progressive, intrinsic, and deleterious functional and structural changes that usually begin to manifest themselves in reproductive maturity and eventually culminate in death." A hallmark of aging is individual variability. Changes due to aging are intrinsic and should be considered independently from external factors such as disease. The sound of our voice changes in pitch and vocal quality as we grow older. He compared the voice of actress Katherine Hepburn on two occasions separated by 50 years, involving factors, such as speech rate and articulation. He discussed the underlying physiology of voice production. With age, the primary effect on the vocal tract is muscle atrophy, which in relation to aging is called sarcopenia. He discussed the respiratory system. The primary change that influences voice is calcification of the costal cartilages and weakening of respiratory muscles, which leads to decreased respiratory capacity. A big cause of an increased effort to get the voice to work is what happens at the level of the larynx.