The Manual lists the elements of an online audio citation such as a podcast:
Podcast:
Darcy Steinke, interview with Sam Tanenhaus and Dwight Garner, New York Times Book Review, podcast audio, April 22, 2007,
http://podcasts.nytimes.com/podcasts/2007/04/20/21bookupdate.mp3.
Citations in a bibliography are formulated in a similar way to a footnote or endnote, but do have slight variations from the way a footnote or endnote is formulated.
Podcast:
Steinke, Darcy. Interview with Sam Tanenhaus and Dwight Garner. New York Times Book Review. Podcast audio. April 22,
2007. http://podcasts.nytimes.com/podcasts/2007/04/20/21bookupdate.mp3.