Within the last decade the advances in otology have been especially marked along two lines, one of which derived its impetus from physics; the other, from the biologic sciences. The pioneer work of Seashore, who perceived the necessity of more accurately measuring and recording the minimum audibility of sound, produced the siren audiometer, which has been modified and improved during the intervening years. This was followed by the Western Electric audiometer from the scientific department of the American Telephone Company, whose investigations to perfect the methods of transmission of sound, and especially of the voice, resulted in several instruments for testing minimum audibility. From the biologic side, increased knowledge of the function of the ear has been especially associated with the names of Magnus and his co-workers in Europe and of Maxwell and others in this country. From these has come a clearer perception of the function of the complex