Ah now, the book has this covered in two ways - one is that it acknowledges uncertainty over the words tynpanum and tiompán &/or even tympanon, and how they where used (pretty flexibly) and discusses it. Witness the words whiskey and whisky. The second is it is not a categorical aspect - the author accepts the uncertainty and refers readers on to the Morcuse's Dictionary but as it is an op cit I have to wade through 7 pages to find the first ref. maybe tomorrow. There are plenty of first-hand accounts of people referring back to the thirties and the Bodhran at a fleadh. The wealth of referrences and the author's botany degree ensures her interest from the winnowing of wheat start-point but she did emminent research and deserves more than a cursory glance in this thread.
To say that Ireland does not have a long history of drumming is clearly false: witness the apprentice boys parades, different but for political as much as practical reasons.