For auditory theory it would be highly important to know the properties of the action currents set up in the VIII nerve by sounds of various frequencies. In these experiments cats were used because of previous work on nerve conduction in this animal and because of the fairly high level of development of the cat in the animal scale, particularly in acoustic sense. A suitable apparatus was developed and the procedure of the experiments consisted in leading off the action currents through electrodes on the nerve through an amplifying system to a detecting apparatus. Parallel with this system, a telephone circuit led from the operating room to a sound-proof room 60 feet away. In the course of the experiments the sound could thus be alternated for comparison. There is evidence of a positive relationship between the voltage established in the nerve and the intensity of the stimulating sound. Considerable attention was given to the possibility of mechanical resonance of the electrodes by trying them on other tissues. If out of the vicinity of the nerve, they never gave the response. A polarizing current nullified the response, which returned after the removal of the current from the nerve. The effects heard in the amplifying system are hence of cochlear origin, and the authors conclude against the possibility of any mechanical jarring of either nerve or electrodes to produce the characteristic response. Experiments were made to verify the fact that there was no variation in inter-electrode potential independent of the control condition. Check experiments indicate that the acoustical response is due to action currents in the auditory nerve. The studies are to be continued and extended. Two apparatus figures.(PsycINFO Database Record (c) 2016 APA, all rights reserved)