Feeney M Patrick, Keefe Douglas H, Sanford Chris A
University of Washington, Otolaryngology, Head and Neck Surgery, V. M. Bloedel Hearing Research Center, Box 357923, Seattle, WA 98195, USA.
Ear Hear. 2004 Oct;25(5):421-30. doi: 10.1097/01.aud.0000145110.60657.73.
The purpose of this study was to develop a method for acoustically measuring the ipsilateral acoustic stapedius reflex threshold by using wideband shifts in energy reflectance and admittance.
A group of 27 young adult subjects with normal hearing participated in the study. Contralateral reflex thresholds were first measured for a 4000 Hz activator tone (maximum level, 92 dB SPL), using a clinical method with a 226 Hz probe tone. Ipsilateral and contralateral reflex thresholds were then measured by using an experimental wideband reflectance and admittance system that used a band-filtered click (200 to 2000 Hz) as the probe stimulus, presented simultaneously with the 4000 Hz activator tone. Reflex thresholds for the wideband system were determined by using statistical tests of the magnitude of the reflex responses as well as their correlation with other reflex responses.
Clinical and experimental reflex thresholds were obtained for 9 of the 27 subjects for all conditions. Clinical reflex thresholds were absent for 8 subjects for whom experimental reflex thresholds were present and were present for 5 subjects who had absent experimental reflex thresholds for one or more conditions. An additional 5 subjects had absent reflex thresholds in all conditions, consistent with the low maximum level of the activator. Wideband measures of contralateral reflex thresholds were approximately 3 dB lower than those obtained with the clinical system. The magnitudes of the group means of the reflex responses were similar for ipsilateral and contralateral stimulations.
Wideband measures of reflectance and admittance may be used to estimate the ipsilateral acoustic stapedius reflex threshold by separating in frequency the spectral energies of the wideband probe stimulus from the activator stimulus. This technique holds promise for measuring reflex thresholds for individuals with absent reflex thresholds through the use of standard clinical methods.
本研究的目的是开发一种通过利用能量反射率和导纳的宽带变化来声学测量同侧镫骨肌声反射阈值的方法。
一组27名听力正常的年轻成年受试者参与了该研究。首先使用226 Hz探测音的临床方法测量4000 Hz激活音（最大声压级，92 dB SPL）的对侧反射阈值。然后使用实验性宽带反射率和导纳系统测量同侧和对侧反射阈值，该系统使用带通滤波的短声（200至2000 Hz）作为探测刺激，并与4000 Hz激活音同时呈现。通过对反射反应幅度及其与其他反射反应的相关性进行统计测试来确定宽带系统的反射阈值。
在所有条件下，27名受试者中有9名获得了临床和实验反射阈值。8名受试者存在实验反射阈值但临床反射阈值缺失，5名受试者在一种或多种条件下实验反射阈值缺失但临床反射阈值存在。另外5名受试者在所有条件下反射阈值均缺失，这与激活音的低最大声压级一致。对侧反射阈值的宽带测量值比临床系统获得的值低约3 dB。同侧和对侧刺激的反射反应组均值幅度相似。
宽带反射率和导纳测量可用于通过在频率上分离宽带探测刺激与激活刺激的频谱能量来估计同侧镫骨肌声反射阈值。这项技术有望通过使用标准临床方法为反射阈值缺失的个体测量反射阈值。
