Brian Sibley has posted the audio presentation of "Microphones in Middle-earth" that was released in 2003 (there are other versions, I believe) on SoundCloud for anyone who hasn't heard this before.

https://soundcloud.com/brian-sibley/se ... crophones-in-middle-earth

THE LORD OF THE RINGS: Microphones in Middle-earth. A behind-the-scenes story of the making of the classic 1981 BBC Radio serialisation.
Written and presented by Brian Sibley and featuring Michael Bakewell, Oz Clarke, Marian Diamond, James Kearney, Peter Jackson, Laura Marples, John McAndrew, Jane Morgan, Bill Nighy, Ian Smith and Peter Woodthorpe. Produced by Jane Morgan. This specially recorded feature was originally included as an 'extra' disc in the 2003 CD Collectors Edition