Department of Biomedical Engineering, College of Engineering, University of Miami, 1251 Memorial Drive, 219A Coral Gables, Florida 33146, USA.
J Acoust Soc Am. 2010 Oct;128(4):1833-44. doi: 10.1121/1.3467769.
Transient-evoked otoacoustic emissions (TEOAE) are responses generated within the inner ear in response to acoustic stimuli and are indicative of normal cochlear function. They are commonly acquired by averaging post-stimulus acoustic responses recorded near the eardrum in response to brief stimuli such as clicks or tone pips. In this study a new long duration stimulus consisting of a frequency swept tone is introduced for the acquisition of TEOAEs. Like stimulus frequency generated OAEs, swept-tone responses contain embedded OAEs. With swept-tone analysis, OAEs can be recovered by convolving it with a time reversed swept-tone signal resulting in time-compression. In addition, higher order nonlinear OAE responses were removed from the linear TEOAE. The results show comparable phase and time-frequency properties between the click and swept-tone evoked OAEs. Swept-tone acquisition of TEOAEs has beneficial noise properties, improving the signal to noise ratio by 6 dB compared to click evoked responses thus offering testing time savings. Additionally, swept-tone analysis removed synchronized spontaneous OAE activity from the recordings of subjects exhibiting such responses in conventional click TEOAEs. Since swept-tone stimulus consists of a single frequency component at any instantaneous moment, its analysis also provides for direct comparison with stimulus-frequency OAEs and click evoked OAEs.
瞬态诱发耳声发射（TEOAE）是内耳对声刺激产生的反应，表明耳蜗功能正常。它们通常通过平均记录在鼓膜附近的声刺激后的声响应来获取，这些声刺激包括短声如 click 或 tone pips。在这项研究中，引入了一种新的长持续时间刺激，由频率扫描的音调组成，用于获取 TEOAEs。与刺激频率产生的 OAE 一样，扫描音调响应包含嵌入式 OAE。通过与时间反转的扫描音调信号卷积，可以恢复 OAE，从而实现时间压缩。此外，从线性 TEOAE 中去除了高阶非线性 OAE 响应。结果表明，click 和扫描音调诱发的 OAE 在相位和时频特性上具有可比性。与 click 诱发的响应相比，扫描音调采集 TEOAEs 的噪声特性具有有益的特性，信噪比提高了 6dB，从而节省了测试时间。此外，扫描音调分析还从常规 click TEOAEs 中具有此类反应的受试者的记录中去除了同步自发 OAE 活动。由于扫描音调刺激在任何瞬时都只包含一个频率分量，因此其分析还可以与刺激频率 OAE 和 click 诱发的 OAE 进行直接比较。
