This thesis addresses two general themes regarding obliteration in ear surgery. First the value of obliteration is evaluated. Considerations needed to be made in regard to performing mastoid obliteration are discussed in the second part. Mastoid obliteration has a long history which is marked by failures and successes. For the last decades it became more and more popular presumably because of the added value of MRI with diffusion weighted imaging during follow up. There are three main techniques in which obliteration can be performed: 1. Canal wall up mastoidectomy with obliteration, 2. Revision radical cavity surgery with obliteration of the mastoid and reconstruction of the canal wall, and 3. Subtotal petrosectomy. All techniques resulted in very favourable results in case of safe, dry and disease-free ears. Technique 1 and 2 also showed significant hearing improvement post-operatively. In case of the considerations it was shown that it is safe to obliterate a mastoid with the presence of a labyrinthine fistula. No residual disease was found at the location of the fistulae. Next to the opinion of the ENT-physician it is even more important to know how patients experience ear surgery and the postoperative situation. Therefore the Chronic Ear Survey was translated into the Dutch language and validated for use at the outpatient clinic. Despite the postoperative hearing improvement many patients still needed a hearing aid. It was shown that because of the postoperative dry ears patients who earlier had a radical cavity now were able to wear a conventional hearing aid.