Equilibrial disturbances caused by hearing aids in hard of hearing children

To 22 hard-of-hearing school pupils a 2 sec. tone pip of 1500 Hz was presented at 120 to 130 dB SPL's (equals 113-123 dB ISO) to both (=44) ears. In 32 of the ears (?) the sound stimulus elicited an ENG change and thus a possible disturbance of equilibrium, 2 cases of type A, 3-10 sec. nystagmus; I case of type B, with continuing nystagmus; 3 cases of type C, with strengthening nystagmus; and I case of type D, with direction-changing nystagmus, were found. We conclude that, in perceptive hearing defects, the maximum output of hearing aids should be limited to 120 dB, not only because of the effect on hearing thresholds. but also on the equilibrial sense. Again we recommend that hearing aids should not be used in those surroundings where loss of equilibrium is dangerous.