There has long existed a need, which has been expressed by otologists and others interested in persons who are hard of hearing, for a disinterested comparison of the performance characteristics of portable commercial carbon microphone hearing aids. In 1934 Dr. Horace Newhart, as chairman of the Committee of Deafness Prevention and Amelioration of the American Academy of Ophthalmology and Otolaryngology, proposed that an investigation be undertaken to determine whether significant differences exist between the hearing aids of various manufacturers. With the help of funds supplied by the Graduate School Research Committee of the University of Minnesota the proposed investigation was commenced in July 1934 as a joint project of the Division of Otolaryngology and of the Electrical Engineering Department.
It was the original plan to test the products of the leading and representative manufacturers of portable carbon microphone hearing aids and thereupon to make an attempt