During his high school years in Missouri, Carl wanted to be an athlete. He excelled in several sports, including football and basketball, but baseball was his favorite. Carl's interest in playing sports shifted to other activities after he contracted a polio-related virus before his senior year in high school. The illness affected the strength in his legs for the remainder of his life and caused him to begin training his voice for a career in broadcasting. Carl entered extemporaneous speech and debate competitions while still in high school, and won an American Legion oratorical contest during his senior year.