Shi Y, Polyakov A, Pratt H
Evoked Potentials Laboratory, Behavioral Biology, Technion-Israel Institute of Technology, Haifa.
Hear Res. 1997 Aug;110(1-2):259-65. doi: 10.1016/s0378-5955(97)00088-9.
Monaural and binaural 11/s, 65 dB pe SPL clicks with interaural time and intensity disparities known to affect central auditory processing were used to study contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) in 10 subjects (20 ears). Psychophysical assessment of sound lateralization induced by the same stimuli was also conducted. TEOAEs were recorded to monaural (ipsilateral to the OAE recording probe) and to binaural clicks when clicks to the contralateral ear were synchronous and symmetrical in intensity, or, in the binaural intensity disparity conditions, synchronous but 10 dB higher or 10 dB lower in the ear contralateral to the OAE recording probe. When interaural time disparities were studied, the clicks to the contralateral ear were of the same intensity throughout, but 400 micros earlier or 400 micros later than to the ear with the probe. The TEOAE components at 13-15.8 ms showed suppression, relative to monaural responses, under all binaural conditions. This contralateral suppression did not correlate with the psychophysical findings. Suppression effects were more pronounced with binaural disparity than with binaurally symmetrical clicks. Thus, although contralateral click intensity was the same with time disparities, suppression was paradoxically enhanced compared to the binaurally symmetrical stimulation. To explain these results we propose that two factors are involved in TEOAE suppression with binaural clicks: (1) contralateral intensity and (2) interaural disparity (time or intensity). The latency of the suppressions observed, the effect of interaural disparity on these suppressions, coupled with the anatomical origin of the crossed efferent fibers and the disparity sensitivity of the superior olivary complex (SOC), all suggest SOC involvement in these TEOAE suppressions.
使用单耳和双耳11/s、65 dB pe SPL短声，其耳间时间和强度差异已知会影响中枢听觉处理，以研究10名受试者（20只耳）中瞬态诱发耳声发射（TEOAEs）的对侧抑制。还对相同刺激诱发的声音定位进行了心理物理学评估。当对侧耳的短声在强度上同步且对称时，或者在双耳强度差异条件下，对侧耳的短声与OAE记录探头对侧耳的短声同步但高10 dB或低10 dB时，记录单耳（与OAE记录探头同侧）和双耳短声的TEOAEs。在研究耳间时间差异时，对侧耳的短声强度始终相同，但比探头所在耳的短声早400微秒或晚400微秒。在所有双耳条件下，相对于单耳反应，13 - 15.8毫秒的TEOAE成分均显示出抑制。这种对侧抑制与心理物理学结果无关。双耳差异时的抑制效应比双耳对称短声时更明显。因此，尽管在时间差异时对侧短声强度相同，但与双耳对称刺激相比，抑制反而增强。为了解释这些结果，我们提出在双耳短声诱发的TEOAE抑制中涉及两个因素：（1）对侧强度和（2）耳间差异（时间或强度）。观察到的抑制潜伏期、耳间差异对这些抑制的影响，再加上交叉传出纤维的解剖学起源和上橄榄复合体（SOC）的差异敏感性，均表明SOC参与了这些TEOAE抑制。
