Bassim Marc K, Miller Roger L, Buss Emily, Smith David W
Hearing Research Laboratories, Division of Otolaryngology-Head and Neck Surgery, Duke University Medical Center, Box 3550, Durham, NC 27710, USA.
Hear Res. 2003 Aug;182(1-2):140-52. doi: 10.1016/s0378-5955(03)00190-4.
The present data were collected in humans to characterize the effects of monaural and binaural stimulation and contralateral noise on the 2f1-f2 distortion-product otoacoustic emission (DPOAE) adaptation response. DPOAE levels (f2/f1=1.21, L1=70 dB SPL, L2=65 dB SPL) were measured in both ears for a range of f2 frequencies (1.2 to 10.0 kHz). The f2 frequency producing the largest amplitude DPOAE was used for further testing employing three different stimulus conditions: the primary tones were presented to only one ear for 4 s; the two tones were presented simultaneously in both ears; and, contralateral broadband noise (60 dB SPL) was presented for 5 s, beginning 4 s after the onset of the monaural primaries in the test ear. Acoustic reflex thresholds were measured to verify that the middle-ear muscles played no systematic role in the measured DPOAE reductions. Estimates of monaural rapid adaptation levels and time constants agreed well with previous human findings. The magnitude of the rapid adaptation under binaural stimulation, as compared with monaural primaries, was 25% greater on average, though adaptation time constants were comparable. With added contralateral noise, the average DPOAE suppression was 1.1 dB (0.3-2.7 dB). The magnitude of the monaural adaptation and the effects of binaural and contralateral stimulation, however, were smaller than those measured previously in experimental animals, though the time constants were in good agreement.
本研究收集了人体数据，以表征单耳和双耳刺激以及对侧噪声对2f1-f2畸变产物耳声发射（DPOAE）适应反应的影响。在双耳中测量了一系列f2频率（1.2至10.0 kHz）下的DPOAE水平（f2/f1 = 1.21，L1 = 70 dB SPL，L2 = 65 dB SPL）。产生最大幅度DPOAE的f2频率用于进一步测试，采用三种不同的刺激条件：仅向一只耳朵呈现初始音4秒；双耳同时呈现两个音调；并且，在测试耳中单耳初始音开始4秒后，呈现对侧宽带噪声（60 dB SPL）5秒。测量声反射阈值以验证中耳肌肉在测量的DPOAE降低中没有系统性作用。单耳快速适应水平和时间常数的估计与先前人体研究结果非常吻合。与单耳初始音相比，双耳刺激下快速适应的幅度平均大25%，尽管适应时间常数相当。添加对侧噪声后，平均DPOAE抑制为1.1 dB（0.3 - 2.7 dB）。然而，单耳适应的幅度以及双耳和对侧刺激的影响小于先前在实验动物中测量的结果，尽管时间常数吻合良好。
