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ABR and EEG were studied in 32 cases of acute anoxia. The ABR showed wave I to wave V in 19 cases and only wave I or no response in 13 cases. However, the EEG was isoelectric in 18 out of 25 cases. The acid-base equilibrium of the cases was inclined to acidosis; therefore, the effect of acidosis on EEG and disturbance of the brain tissue due to anoxic state were suspected. As the effect on the brain stem, a direct effect and secondary effect or brain ischemia arising from increased intra-cranial pressure and a subsequent fall in the brain perfusion pressure were suggested.

The effect of band noise masking on persistent tinnitus was investigated in 191 patients. The effect of tinnitus masker was evaluated by the patient's complaints after two hours' masking. The causes of tinnitus in eluded pesbycusis, nose dnduced deafness, endlymphatic hydrops, sudden deafness sensorineural deafness of unknown etiology.The band noise masker was most effective on tinnitus due to presbycusis. Other influential factors in the effect of the tinnitus masker were age and hearing level at the tinnitus frequency. The suppression of tinnitus was more prominent in older patients and the patients whose hearing levels of the tinnitus frequencies were less than 30dBHL.