[Hearing aid prescription in ENT practice. II. Forms of hearing aid construction and prescription of bilateral hearing aids].

The fundamental constructional types of hearing aids are box or pocket hearing aids, behind-the-ear devices and in-the-ear devices. Other special forms include hearing aid spectacles. The indications for prescription of the various constructional types are described with consideration of their advantages and disadvantages, supplemented by a comment on the legal aspects of prescription of in-the-ear aids. In binaural deafness, provision of hearing aids for both ears is to be regarded as the normal approach with careful observation of the limits of the indications. The advantages of hearing in both ears compared with monaural hearing, and the contra-indications to binaural provision of hearing aids are described in detail. The legal basis of binaural hearing aid provision is explained.