For discussion’s sake – while I don’t know the specific nature of your videos, my guess is that they might be demonstrating various techniques or other content in which simply hearing the audio of the video wouldn’t deliver the full context of the content. If making that content accessible is something you’d want to do, you’d likely want to start with a written description of what takes place in the video. Beyond that, high contrast vector images or diagrams showcasing specific parts of the technique would certainly help.
To be protected by the ADA, one must have a disability, which is defined by the ADA as a physical or mental impairment that substantially limits one or more major life activities, a person who has a history or record of such an impairment, or a person who is perceived by others as having such an impairment. The ADA does not specifically name all of the impairments that are covered.
On September 25, 2008, President George W. Bush signed the ADA Amendments Act of 2008 (ADAAA) into law. The amendment broadened the definition of "disability", thereby extending the ADA's protections to a greater number of people. The ADAAA also added to the ADA examples of "major life activities" including, but not limited to, "caring for oneself, performing manual tasks, seeing, hearing, eating, sleeping, walking, standing, lifting, bending, speaking, breathing, learning, reading, concentrating, thinking, communicating, and working" as well as the operation of several specified major bodily functions. The act overturned a 1999 US Supreme Court case that held that an employee was not disabled if the impairment could be corrected by mitigating measures; it specifically provides that such impairment must be determined without considering such ameliorative measures. It also overturned the court restriction that an impairment which substantially limits one major life activity must also limit others to be considered a disability. In 2008, the United States House Committee on Education and Labor stated that the amendment "makes it absolutely clear that the ADA is intended to provide broad coverage to protect anyone who faces discrimination on the basis of disability." Thus the ADAAA led to broader coverage of impaired employees.