Department of Communication Sciences and Disorders, East Carolina University, Health Sciences Building, East Carolina University, Greenville, NC 27858, USA.
Ear Hear. 2012 May-Jun;33(3):421-9. doi: 10.1097/AUD.0b013e31823effd9.
In previous studies, otoacoustic emissions (OAEs) have been found to be larger in normal-hearing children with sickle cell disease (SCD). It was hypothesized that some dysfunction or reduction in the medial olivocochlear efferent suppression of outer hair cell activity was responsible for this phenomenon. To test this hypothesis, contralateral suppression of transient-evoked otoacoustic emissions (TEOAEs) was examined in children with and without SCD.
Thirteen African American school-aged normal-hearing children with homozygous SCD and 13 age- and gender-matched control children participated. TEOAEs were obtained bilaterally with 80 dB peSPL nonlinear click stimuli. To examine contralateral suppression, TEOAEs were obtained with 60 dB peSPL linear click stimuli with and without a contralateral 65 dB SPL white noise suppressor.
Overall and half-octave band TEOAE levels were found to be larger in children with SCD relative to the normal control children (p < 0.05), consistent with previous reports of increased OAE levels. There was no significant difference (p > 0.05) in the absolute or proportional amount of TEOAE suppression as a function of group and ear. There were also no significant correlations or linear predictive relationships between TEOAE suppression and TEOAE level for either ear or group (p > 0.05).
These findings do not support the notion that increased OAE levels in children with SCD are a consequence of abnormal medial olivocochlear system function as assessed with contralateral suppression of TEOAEs.
在以往的研究中，已发现镰状细胞病（SCD）正常听力儿童的耳声发射（OAE）较大。有人假设，内侧橄榄耳蜗传出对毛细胞活动的抑制作用有些功能障碍或减少，导致了这种现象。为了验证这一假设，研究人员检查了 SCD 患儿和无 SCD 患儿的瞬态诱发耳声发射（TEOAE）的对侧抑制情况。
13 名非裔美国学龄期 SCD 同合子正常听力儿童和 13 名年龄和性别匹配的对照组儿童参与了这项研究。采用 80dB peSPL 非线性 click 刺激，双侧获得 TEOAEs。为了检查对侧抑制，采用 60dB peSPL 线性 click 刺激，双侧获得 TEOAEs，同时在对侧施加 65dB SPL 白噪声抑制器。
与正常对照组儿童相比，SCD 儿童的总体和半倍频带 TEOAE 水平较高（p < 0.05），这与先前报道的 OAE 水平升高一致。组间和耳间 TEOAE 抑制的绝对量或相对量无显著差异（p > 0.05）。对于任一只耳朵或任何一组，TEOAE 抑制与 TEOAE 水平之间也没有显著的相关性或线性预测关系（p > 0.05）。
这些发现不支持这样的观点，即 SCD 儿童 OAE 水平升高是由于对侧抑制 TEOAE 评估的内侧橄榄耳蜗传出系统功能异常所致。
