Electrical Currents Associated with Sound Reception by the Ear

The remarkable phenomenon of the reproduction of voice sounds and musical tones entering the cat's ear, by amplification of electrical currents from the eighth nerve and neighboring structures, observed by Wever and Bray, 1 has been confirmed by Davis and Saul, 2 Adrian, 3 Hughson and Crowe 4 and by Witting. 5 ∗ If the view held by the discoverers of this phenomenon is substantiated, that these currents represent true action currents related to hearing, it will necessitate a marked revision of our present views in regard to the refractory period and frequency of impulse transmission in sensory nerves, or else the assumption of an elaborate coordinating mechanism.

We have found the same phenomenon in the dog under sodium barbital or nembutal anesthesia. Using a 6 stage amplifier, sufficient volume is obtained to make clear records on a phonographic recorder. Words, sentences and single frequencies between 100 and more than 5000 per second are clearly reproduced. Our results, in part confirming, in part supplementing, and in part contrary to previous observations may be summarized as follows :

1. In common with previous workers we find that the phenomenon may be adduced by leads not only from the eighth nerve but also over a rather large contiguous region and in the neighborhood of the cochlea. With one electrode on the cut surface of muscle several centimeters away from the nerve, we have obtained positive results of varying degree of intensity writh the other electrode (a) on the eighth nerve, (b) on the tenth nerve, (c) near the round window-within the bulla (Adrian), (d) on the neighboring cerebellar cortex, (e) on the bony tentorium, (f) on the neighboring cerebral cortex, (g) within the external auditory meatus, and finally (h) on the occipital bone.