What is the oldest recorded sound in history? For over 100 years researchers thought they knew until a mind-blowing discovery by historians found something new - and technological advances allowed it to be played back for the first time in history. What is the oldest recording of a musical performance, president, battlefield, television broadcast, cell phone call, and more? Featuring Patrick Feaster, co-founder of FirstSounds.org, three-time Grammy nominee, and Ph.D. in Musicology as well as Lynn Novick, award-winning filmmaker, and co-directing partner of Ken Burns.Twenty Thousand Hertz is produced out of the studios of Defacto Sound and hosted by Dallas Taylor.Consider supporting the show at donate.20k.orgEpisode transcript, music, and credits can be found here.