Comparing stimulus-frequency otoacoustic emissions measured by compression, suppression, and spectral smoothing
Comparing stimulus-frequency otoacoustic emissions measured by compression, suppression, and spectral smoothing
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DOI：
10.1121/1.2793604
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发表时间：
2007-12-01
影响因子：
2.4
通讯作者：
Shera, Christopher A.
中科院分区：
文献类型：
--
作者：
Kalluri, Radha;Shera, Christopher A.
刺激频率耳声发射（SFOAE）已通过多种不同的方式进行测量，包括（1）非线性压缩，（2）双音抑制和（3）频谱平滑。这三种方法中的每一种都利用不同的耳蜗现象或信号处理技术来提取发射。压缩方法利用发射振幅相对于刺激的线性增长的压缩增长。发射被定义为在一个强度下测量的耳道压力与在更高强度下测量的重新缩放的压力之间的复差，其中发射被假定为可忽略不计。抑制方法将SFOAE定义为在附近频率处使用和不使用抑制音测量的耳道压力之间的复差。抑制音被假定为基本上减少或消除发射。频谱平滑方法涉及将复杂的耳道压力频谱与平滑函数进行卷积。该分析利用不同的潜伏期的刺激和发射，相当于在相应的潜伏期域的窗口。虽然这三种方法通常被认为产生相同的排放，但没有等效性。曾经建立。本文比较了人类SFOAE测量的三种方法使用的程序，控制时间漂移，污染的校准诱发发射，和其他潜在的混乱。在低刺激强度下，使用所有三种方法测量的SFOAE几乎相同。在较高的强度，程序的限制有助于小的差异，虽然一般的光谱形状和相位的三个SFOAE保持相似。通过压缩、抑制和频谱平滑测量的SFOAE的近似等效性表明，SFOAE特性不仅仅是测量方法的伪影。(c)2007年，美国声学学会。
Stimulus-frequency otoacoustic emissions (SFOAEs) have been measured in several different ways, including (1) nonlinear compression, (2) two-tone suppression, and (3) spectral smoothing. Each of the three methods exploits a different cochlear phenomenon or signal-processing technique to extract the emission. The compression method makes use of the compressive growth of emission amplitude relative to the linear growth of the stimulus. The emission is defined as the complex difference between ear-canal pressure measured at one intensity and the rescaled pressure measured at a higher intensity for which the emission is presumed negligible. The suppression method defines the SFOAE as the complex difference between the ear-canal pressure measured with and without a suppressor tone at a nearby frequency. The suppressor tone is presumed to substantially reduce or eliminate the emission. The spectral smoothing method involves convolving the complex ear-canal pressure spectrum with a smoothing function. The analysis exploits the differing latencies of stimulus and emission and is equivalent to windowing in the corresponding latency domain. Although the three methods are generally assumed to yield identical emissions, no equivalence has. ever been established. This paper compares human SFOAEs measured with the three methods using procedures that control for temporal drifts, contamination of the calibration by evoked emissions, and other potential confounds. At low stimulus intensities, SFOAEs measured using all three methods are nearly identical. At higher intensities, limitations of the procedures contribute to small differences, although the general spectral shape and phase of the three SFOAEs remain similar. The near equivalence of SFOAEs measured by compression, suppression, and spectral smoothing indicates that SFOAE characteristics are not mere artifacts of measurement methodology. (c) 2007 Acoustical Society of America.