In 2008, Patrick Feaster, a researcher and educator specializing in early sound media, and his colleagues revolutionized the field of historical sound recording. They suggested that attempts to record sound waves as visual tracings almost two decades before Thomas Edison's 1877 phonograph could be "played back" as sound.

In this discussion with Dario Robleto, Feaster speaks about his work and their recent collaboration in "playing back" the earliest 19th-century attempts to visually record the human heartbeat.