Communication forms the foundation of social interaction. For older adults, however, there is known to be an increased risk of developing conditions that interfere with the ability to communicate. These conditions may occur for a variety of reasons, including age-related changes in physical or sensory functioning, injury, and disease. It is iii Dedication I would like to dedicate this work to my parents, to my wife Kristine, to the many patients that I have learned so much from over the years, and also to the memory of Rob Williams whose untimely loss is still a source of sadness.iv Acknowledgments