Sprague B H, Wiley T L, Block M G
Audiology. 1981;20(1):15-40. doi: 10.3109/00206098109072680.
Acoustic reflex growth was measured as a function of activator bandwidth in 10 subjects with normal hearing and in 5 subjects with different configurations of sensorineural hearing loss. The activators consisted of tones with frequencies of 500, 1 000 and 4 000 Hz, fractions and multiples of octave bands centered at these frequencies, and broadband noise. Growth functions for the normal-hearing subjects measured with a 660-Hz probe tone had smaller peak magnitudes and shallower slopes than the growth functions measured with a 220-Hz probe tone. The slope of the growth function and the peak magnitude of acoustic impedance were not affected in any consistent manner by activator bandwidth or activator center frequency. The dynamic range of the growth function increased with an increase in activator bandwidth beyond 1 octave. The resistive component of acoustic impedance did not exhibit a consistent pattern of change with increasing activator intensity level. The reflex growth functions for normal-hearing subjects separated into two groups, those with steep slopes and large peak magnitudes and those with shallow slopes and small peak magnitudes. 3 out of the 5 cases with sensorineural hearing loss presented growth functions with shallower slopes, smaller dynamic ranges and smaller peak magnitudes than normal. The other 2 cases had steeper slopes and larger peak magnitudes than normal. The dynamic range did not increase with an increase in activator bandwidth beyond 1 octave. The differences in reflex growth functions with probe-tone frequency observed for the normal group were diminished or absent in 4 of the 5 cases of sensorineural hearing loss. The frequency of 4 000 Hz appeared to be the most sensitive to reflex manifestations of hearing loss.
在10名听力正常的受试者和5名患有不同类型感音神经性听力损失的受试者中，测量了声反射增长与激活器带宽之间的函数关系。激活器包括频率为500、1000和4000Hz的纯音、以这些频率为中心的倍频程带的分数倍和倍数倍以及宽带噪声。用660Hz探测音测量的听力正常受试者的增长函数，其峰值幅度较小，斜率较浅，低于用220Hz探测音测量的增长函数。激活器带宽或激活器中心频率并未以任何一致的方式影响增长函数的斜率和声阻抗的峰值幅度。当激活器带宽超过1倍频程时，增长函数的动态范围随着带宽的增加而增大。声阻抗的电阻分量并未随着激活器强度水平的增加而呈现出一致的变化模式。听力正常受试者的反射增长函数分为两组，一组斜率陡峭、峰值幅度大，另一组斜率浅、峰值幅度小。5例感音神经性听力损失患者中有3例的增长函数斜率较浅、动态范围较小且峰值幅度小于正常。另外2例的斜率比正常情况更陡峭，峰值幅度更大。当激活器带宽超过1倍频程时，动态范围并未随着带宽的增加而增大。在5例感音神经性听力损失病例中的4例中，正常组中观察到的探测音频率与反射增长函数之间的差异减小或不存在。4000Hz的频率似乎对听力损失的反射表现最为敏感。
