ＩＬＯ８８による誘発耳音響放射と聴力レベルの関連について Relationship between the severity of cochlear deafness and eOAE recorded by ILO88.
Kemp & Bray製作のILO88を用いて内耳性難聴者90名154耳のclickに対するeOAEを測定し, 内耳性難聴の程度との関連を検討した。 (1), eOAE波形が認められかつ再現性が40%以上の場合をeOAE (+) とすると, 0.5k-4kHzの4周波数平均聴力が35dB未満の81耳では, 94%の確実性でeOAE記録が可能, 35dB以上の73耳及び40dB以上の63耳では, 89%及び92%の確実性でeOAE記録が不能であった。 1kHzと2kHzの2周波数平均聴力が40dB以上の64耳では, 94%の確実性でeOAE記録が不能であった。 (2), eOAE記録可能の84耳では, 内耳性難聴の程度とeOAEパワー (total echo power及びFFT解析図のhighest peak power) の間に負の相関 (r=-0.44) が認められた。 以上の結果から, ILO88を用いて, 4周波数平均聴力レベル35-40dB以上の内耳性難聴のスクリーニングが可能と思われた。
After recording evoked otoacoustic emissions (eOAE) to click in 154 ears of 90 patients with cochlear deafness by using ILO88 which was made by Kemp and Bray for recording and analysing eOAE easily, the relationship between eOAE and severity of cochlear deafness was studied. The results obtained were as follows.<br>(1) The severity of hearing loss and eOAE detection.<br>If we judge the presence of eOAE with two criteria, the detection of eOAE wave and the reproducibility more than 40%, eOAE was detected with the reliability of 94% in 81 ears with the mean hearing loss at the 4 frequencies from 500Hz to 4000Hz less than 35dBHL. eOAE was not detected with the reliability of 89% and 92% in 73 and 63 ears with the mean hearing loss at the 4 frequencies more than 35dBHL and 44dBHL, respectively.<br>eOAE was not found with the reliability of 94% in 64 ears with the mean hearing loss at the 2 frequencies 1000Hz and 2000Hz more than 40dBHL.<br>(2) The severity of hearing loss and eOAE power.<br>In 84 ears with eOAE detection, negative correlation (r=-0.44) between the severity of hearing loss and eOAE power was found when total echo power and highest peak power at the frequencies from 1000Hz to 2000Hz in FFT pictures were used as an indicator of eOAE power.<br>From the results mentioned above, we concluded that ILO88 was useful for screening of cochlear deafness with the mean hearing loss more than 35 or 40dBHL at the frequencies from 500Hz to 4000Hz.
- ＡＵＤＩＯＬＯＧＹ ＪＡＰＡＮ
ＡＵＤＩＯＬＯＧＹ ＪＡＰＡＮ 33(2), 110-117, 1990