• Hearing aid selection and hearing aid evaluation are related, but separate, processes. Adequate selection must precede evaluation, which can only be applied to a few of the limitless amplification possibilities. I discuss the theoretical principles of aid selection and illustrate their application by reference to aid selection procedures developed in the National Acoustic Laboratories, Australia. Unless selection is arbitrary, a theoretical method is being used even if not recognized or applied consistently. It is argued that casual methods cannot be adequate and should be replaced by the adoption of theoretical procedures that are explicit, systematic, comprehensive, and subject to critical examination and refinement.
(Arch Otolaryngol 105:519-525, 1979)