Search

身体障害者福祉法の定めるところにより身体障害者手帳を交付された者は, 数々の利益を受けることができる。 しかし, 同法の意義は更生医療と更生への援助であり, 同法15条指定医は正確な聴力検査に基づく等級判定を行う義務がある。 難聴を有する身体障害者が一旦手帳を手にすると, 後日障害等級の改善が確認されても手帳の返還ないし書き換えを求めることが困難となる傾向がある。 このような問題に関する実情は必ずしも解明されているとは限らない。 筆者は県から補装具装用判定の委嘱を受け, 聴力障害者の聴力を再検する機会に恵まれているので, 手帳を所有している障害者の聴力を精検し, 初回検査との関係を調べ, 問題点の解明を試みた。 結果として, 特に高齢者の聴力検査に問題点があることを強調した。

Ten samples of the averaged spontaneous brain activity were made on a sleeping child of 5 years old. On the other hand, from a typical pattern of the averaged evoked response, 5 samples with different amplitudes were prepared. Then each of the 10 samples of the spontaneous activity and each of the 5 samples of the evoked response were composed by using an averaging computer. Two trained examiners independently made the determination of the presence or absence of the evoked response on 41 out of 50 composed samples and 10 samples without evoked response. The decision was also attempted according to an objective standard made by one of the authors. Besides, peak latencies of P2 and N2 as well as P2N2 amplitude were measured on 19 composed samples.Results obtained were summarized as follows:1. There was an individual discrepancy between the examiners as to the detectability of the response.2. False positive decision occured in about 10 to 35 per cent of the judgements.3. Almost 100 per cent detection of the response Was achieved when the amplitude of the evoked response was twice as large as the levels of the averaged background activity.4. The range of so-called “trasition zone” of the evoked response was estimated to cover the range of the stimulus intensity of 40 to 50dB or more.5. The latencies and amplitudes of the evoked response were modified considerably by the background activity.

By mean of the analog computer the evoked electroencephalngraphic responses of the vertex (Cz) during barbital sleep in normal young children to acoustic stimuli were obtained with following results:There were penta-phasic with the components of vertex-positive (P1), negative (N1), positive (P2), negative (N2) and of vertex positive (P3).The peak latencies of these components in children aged 16 days to 3 months were 60 to 80msec (P1), 160 to 210msec (N1), 250 to 340msec (P2), 470 to 690msec (N2) and 820 to 860msec (P3), while those of children aged 1 to 5 years were about 60msec (P1), 130 to 190msec (N1), 270 to 310msec (P2), 420 to 610msec (N2) and 730 to 800msec (P3) respectively.The evoked responses of the children aged 16 days to 3 months appeared at the intensity of 30 to 60dB SPL and in children aged 1 to 5 years 20 to 50dB SPL.The amplitude and the peak latencies of the evoked response varied with the stages of sleep. The major difference between the waking stage and the all stages of sleep were the appearance of P3 and the consistent increase in the peak latencies of N1, P2 and N2 during sleep.