Many oral histories or historic recordings are included in traditional library catalogs and archival finding aids.
Hints for identifying this type of material in library catalogs:
James Whitcomb Riley Recordings Audio of James Whitcomb Riley reciting his poems.
Park Tudor Words of War Oral Histories Collection of oral histories from Hoosiers serving in various wars.
American Memory Sound Recordings There is some limited audio in the Library of Congress American Memory Project. Follow the link provided and type Indiana in the search box.
Irvington Oral Histories Oral history interviews with individuals who lived in Irvington, an Eastside neighborhood of Indianapolis.
Indiana Historical Society
Library of Congress American Folklife Center, Story Corps Collection
Indiana State Library, A-Z List of Oral Histories at ISL