The BBC have used OCR technology on every copy of the UK Radio Times magazine from 1923 to 2009.

Tolkien appears a lot, and possibly some of these recordings were not known about until this resource became available.

There seem to be a lot more adaptions of The Hobbit for the radio than I was aware of ... =12&tf=00%3A00&tt=00%3A00

The BBC also have another page that shows the same results from 2009 to today, but this does not seem to work, which is a shame