PrefaceUp to now, it was generally believed that the destruction of any part of the membranous labyrinth invariably led to complete hearing loss. This concept is no longer accurate!It became apparent that the inner ear was compartmentalized into a cochlea and a vestibule, separated from each other by two valves. Each compartment with its own morphology, physiology, particular biochemistry, and specific pathology. Today, surgery of either of these compartments can be performed without fear for the integrity of the other. This constitutes a revolution in surgery of the inner ear and leads to perspectives which, until recently, could not even be envisaged. A Conference treating the fundamental aspects, concerns of daily practice and surgery of 'Inner Ear Partition' was held. on Saturday, January 25, 1997, at the Fondation Universitaire, Brussels. The intention was to bring together eminent colleagues and the most experienced leaders in the field so that, not only could they share their know-how, but also a consensus could be established of the actual state of the art in the management of various inner ear disorders. Thanks to the constructive participation of all those concerned, the conference achieved its aims and everyone felt able to speak freely, even when expressing opinions which could have been thought to be controversial.The ultimate purpose of the conference was to promote the prospects and possibilities of functional surgery of the inner ear and of tumors of the cerebellopontine angle.I would like to extend my thanks to the many participants who attended the conference and particularly to the speakers who accepted the invitation to participate in this meeting and also to contribute to this publication by submitting carefully prepared manuscripts.It would not have been possible to organize this conference without the substantial support of

the Solvay company. We are extremely grateful to them for their generosity.We are also very grateful to Kugler Publications for making the publication of this book possible.B. Ars.