Abstracts of Technical Papers from Bell System Sources (01 April 1937)

Rev., December 1, 1936. 39th Ann. Mtg. Amer. Soc. for Testing Materials, Vol. 36, 1936--Part II, Papers. Acous. Sor. Amer., January, 1937. 247 248 BELL SYSTEM TECHNICAL JOURNAL stimulation on the basilar membrane has been calculated from data on differential pitch sensitivity. The calculations involve assumptions concerning the choice of the upper and lower pitch limits of hearing and the choice of tone levels which should be used in obtaining differential pitch sensitivity data. 

It is shown that for quite different assumptions the positions of stimulation for tones in the range from 500 to 10,000 cycles are not greatly affected. Outside this range the positions depend on the assumptions. The calculated positions for tones of 1000, 2000 and 4000 cycles fall, respectively, at points on the membrane about f, | and § of its length away from the helicotrema. The calculated positions are compared with positions obtained from post-mortem studies of human cochlea and with positions obtained from electric response measurements on the cochlea of anesthetized guinea pigs. 

The differences between various methods for the most part are no larger than calculated differences between observers. Some Uses of the Torque Magnetometer.4 H. J. WILLIAMS. The history of torque measurement as an index of ferromagnetic anisotropy is outlined. A simple magnetometer for torque measurement is described in detail and uses for the instrument are discussed. These include the measurement of anisotropy constants, coercive force, complete magnetization curves for single directions, and rotational hysteresis losses.