[Experimental studies on the influence of electric and light stimulation upon the susceptibility to acoustic trauma].

The present work was designed to study the influence of the stresses upon the inner ear. Guinea pigs were put in the state of stress by using electric stimulation (80V, 0.7sec., at 10sec. intervals) and light stimulation (electronic flash or electric bulb), and the influence of these stimulations upon the inner ear was observed. A) The susceptibility to acoustic trauma in animals was excited by electric or light stimulation: In the control animals, acoustic stimulation with 2000cps of 120phon for every one hour of ten successive days caused only slight degeneraation of the hair-cells, while in the animals excited with electric stimulation at the same time, the severe destruction of the structures of the organ of Corti was observed. Light stimulation did not change the susceptibility to acoustic trauma. B) In the animals excited with electric and light stimulation for 24hours, the result obtained as follows: No pathological change of the inner ear was observed. Preyer's reflex test showed an impairment, but C.M. potentials were mostly unchanged. Sodium decreased in perilymph and increased in endlymph.