A response to a public inquiry about the location from which First Lady Lou Hoover made a radio address that was also filmed for newsreels and shown to the public.
by Carl Sferrazza Anthony, Historian of the National First Ladies Library
Mrs. Hoover had actually established a room in the White House residence from which she both practiced her elocution and from there also delivered at the very least this one public radio address, including the newsreel footage taken of it.
The speech in question was entitled, “The Woman’s Place in the Present Emergency,” and made on behalf of the National Women’s Committee of the Welfare and Relief Mobilization.” It was delivered on 27 November 1932 – three weeks or so after her husband lost his bid for re-election.

Franklin D. Roosevelt delivering one of his fireside chat radio speeches from the White House. (Huffington Post)
It is established fact that just months after the Hoover Administration ended, when President Franklin D. Roosevelt began delivering his “fireside chats” on the radio to the American people that electronic recording and transmission equipment had to be brought into the present-day oval Diplomatic Reception Room.

Lou Hoover making clothes during the Great Depression on a sewing machine, to encourage voluntary aid to those in need. (Library of Congress)
While this is only speculation, it may be that this room was, in fact, used for her radio and newsreel recording as seen in the video (if not all of them) and that contemporary news reports that she practiced her public speaking into a recording device in the same room where she delivered them live to the nation is not, in fact, correct.