Many university presses provide podcast audio interviews with their authors, several of them featuring business historians. One company, Heron & Crane, operates a podcast series on business and management topics called "The Invisible Hand" (most of their audios are free, but some require a payment of $1.99 to download). A sampling from their (free) offerings and others:
Steve Fraser, Wall Street: America's Dream Palace
Harold James, The Creation and Destruction of Value: The Globalization Cycle
Pamela Walker Laird, Pull: Networking and Success since Benjamin Franklin
Thomas McCraw, Prophet of Innovation: Joseph Schumpeter and Creative Destruction
Stephen Mihm, A Nation of Counterfeiters: Capitalists, Con Men, and the Making of the United States
David Nye, When the Lights Went Out: A History of Blackouts in America
Andrew Sandoval-Strausz, Hotel: An American History
Bryant Simon, Everything but the Coffee: Learning about America from Starbucks
David Suisman, Selling Sounds: The Commercial Revolution in American Music