難聴耳における音響遮蔽効果に関する研究

抄録

The masking effects were observed in normal individuals, persons with conductive deafness and persons with sensory neural deafness by auditory stimulus. In the present experiments, two stimuli were used to mask pure tones. One masking stimulus was a white noise, and that of the second was a pure tone of 800 Hz. All measurements were monaural. The relation between the amount of masking at a certain frequency and intensity of the masking stimulus was statistically discussed. The obtained results and conclusions were as follows:
1) At the amount of masking of pure tones by white noise, there was no difference between cases with conductive deafness and cases with sensory neural deafness.
2) In the masking by white noise, statistically, there was a little discrepancy of amount of masking between normal individuals and persons with sensory neural deafness, but similar difference between normal individuals and cases with conductive deafness was observed. Therefore no peculiar masking effects in patients with sensory neural deafness was considerable.
3) The masking effects of pure tones by pure tone of 800Hz had the same influences for cases with hard of hearing as for normal persons, when the intensity of the masking tone was the same relation to the level at the threshold of hearing corrected air-bone gap.
4) By method of measurements of the masking effects, it is difficult to distinguish between inner ear disturbances and ganglion or auditory nerve impairments.