So, thanks to Janice S. for sending me the link about a project the BBC Sound Archive is launching to preserve their older and more fragile material -- much of it on archaic media, going all the way back to wax cyclinders. As with the US film preservation project that's been going on for some years now, they're faced with the problem that the material is disintegrating faster than they're copying it.
Given such a situation, the group doing the preservation has to prioritize, and that's when things get interested for a Tolkienist. Among "a selection of seven of the most important sound recordings currently held in the library, which were among the first to be saved", is one by JRRT, the 1930 Linguaphone Institute language lesson "At the Tobacconist". So according to the BBC Tolkien ranks with Tennyson, Joyce, Florence Nightingale, and the like in historical importance. That's a 'cultural treasure' status that goes beyond popularity or best-sellerdom or any passing fad.
Now if they could only spell his name right (it's 'Tolkein' throughout the entire piece, though the TELEGRAPH seems to have updated their caption to now read 'Tolkien').
Here's the list of the seven:
1. Christabel Pankhurst demanding votes for women
2. Florence Nightingale
4. James Joyce reading from ULYSSES
5. Noel Coward taking a curtain call
6. Tennyson reading a snippet of "The Charge of the Light Brigade"
7. a zither rehearsal for the score of THE THIRD MAN
Some of these I have to take on faith, given the poor quality of the surviving recording: I think the Tennyson must be the oldest one here given that he died in 1892, the year Tolkien was born.
I also have to add the caveat that while it's good to know these recordings are being preserved, in at least the case of Tolkien there are multiple surviving copies of the original recording (I have an original .78 rpm of the Linguaphone recording myself).
Here's the article:
current reading: O'Malley's THE ROOK
UPDATE (Fr. 1/23-15):
As 'Trotter' pointed out in the comments, it's actually the British Library and not the BBC who have launched this laudable project; my mistake.