The improvement and rehabilitation of the hearing for profound sensory hearing loss or totally deaf, induced by either congenital anomalies or acquired sensory damage, is one of the most important task which has been solved in the field of recent rehabilitation science. During the past half a century, a many studies for the deaf was carried out, however the problems remain unsolved. Djourno and Eyries reported in 1957 that an auditory response was produced in a patient with profound sensory deafness by electronic stimulation of a wire which was inserted in the Scala tympani. The authors have expanded on this principle. The receptor organ of corti of the cats were surgically destroyed, rendering the cats totally deaf in each ear. A special Electronic Cochlea, developed by professor Choi Bang Jin of the Department of Engineering at Chonnam University, was then surgically implanted. The device consists of an outer and inner part. The outer device, placed outside body, converts sound in to electric current which is then conducted to the inner device by means of a wireless base. The inner device is implanted in the Scala tympani or Scala vestibuli of the surgically destroyed bullae. The current from the outer device is transmitted by the inner device to the neuron stimulating electrode of the VIII nerve. The authors attempt to expain the nature of auditory sensation induced by sound stimulation of the outer device in experimental cats. The following results were obtained : 1) In the case of the experimentally destroyed organ of the Corti of the cats, a relationship was shown between the intensity of the stimulating sound and the amplitude of the pinna reflex after stimulation. 2) The correlation between the intensity of the stimulation and the pinna reflex is parallel, within a certain range. 3) Upon sound stimulation, the pinna reflex has a refractory period in the implanted cochlea. 4) The pinna reflex showed no signs of fatigue. 5) Preyers pinna reflex was induced by intensive sound stimulation. From these results the authors conclude that auditory sensation could be produced by sound stimulation in humans.