A basis for the prediction of performance of hearing aids

Formerly a hearing aid could only be described as a device purporting to assist defective hearing, and no scientific prediction could be given as to the benefit that could be obtained from a given instrument. The lack of a scientific basis of comparison of these instruments has presented a handicap to otologists and manufacturers and others connected with the industry. The ordinary methods of comparing results with acoustical apparatus are only misleading in the case of hearing aids because they do not take into account the many varying types and degrees of deafness that are to be met with. The object of this paper is to describe a method of obtaining a scientific standard of comparison which does take into account both the acoustical qualities of the instrument and the degree of deafness of any person who may be concerned.