USUALLY audiometric records of the hearing function are taken for the octaves of the (great) C, viz., for the tones of frequencies 128, 256, 512, 1024, 2048, 4096, 8192 H. and with, some audiometers. 9747 cycles per second or a higher value. In this way only eight or nine points of the ideal continuous threshold curve of hearing are fixed. Thus only a rough idea is obtained about the hearing for low, middle and high tones, and all intervening tones are neglected. Since it is known that a great hearing loss may exist in a very small area of the tonal scale, causing a so-called dip, the need of an audiogram more detailed, especially for the higher tones, has become urgent. Some investigators, struggling with the imperfection of the routine audiogram, made threshold determinations for intervening tones. For clinical use, however, it takes too much time to get a result