Total deafness: the need and possibility for a working definition.

There is an urgent need for a definition of total deafness or total hearing loss which would appear to be feasible in terms of audiometric threshold. Considerable care must be taken in providing appropriate instrumentation for measuring the hearing loss of profoundly deaf people, particularly with regard to sufficient acoustic output. Proposals are made for values for the maximum outputs of audiometers. The practical benefit in the management of profoundly deaf people that can be obtained by the introduction of an agreed definition is described.