IIR, Tom is also suggested in the extended edition of TT: a willow tree tries to trap the hobbits, and Treebeard stops it, with some of Tom's lines.

There's still quite a relatively sizeable audience for radio drama in the UK: Radio 4 has an afternoon play six days a week, I think, not to mention other dramatizations, and, of course, The Archers (long-running soap about country life).