The effect of noise exposure on the details of distortion product otoacoustic emissions in humans
The effect of noise exposure on the details of distortion product otoacoustic emissions in humans
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DOI：
10.1121/1.414733
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发表时间：
1996-03-01
影响因子：
2.4
通讯作者：
Kemp, DT
中科院分区：
文献类型：
--
作者：
Engdahl, B;Kemp, DT
从频率、微结构、输入输出函数、主频比调谐曲线和群延时五个不同的范式考察了噪声暴露对失真产物耳声发射(DPOAEs)幅值和相位的影响。目的是调查这些不同特征对中等水平噪声暴露的脆弱性。9名受试者被暴露在三倍频程噪声中。DPOAE的幅度降低了频率，最大的降低大约比噪声频率高半个八度。在低刺激水平时，幅度降低的程度最大。没有观察到对主比调谐曲线形状的影响。在团体延误方面，出现了下降的微弱趋势。在7名受试者中，有5名受试者的振幅与频率之比显示出明显的微观结构。噪声暴露后，显微组织的最大与最小比值减小，整个图形向低频方向移动。在微观结构的周期性中可以看到多次内反射或干涉的证据。利用一个基于多次反射的简单微观结构模型，重新评估了噪声引起的变化。最大与最小微结构比的减小可以解释为内反射系数的减小。讨论了这些观测结果对解释DPOAE测量的影响。(C)1996年美国声学学会。
The effect of noise exposure on amplitude and phase of distortion product otoacoustic emissions (DPOAEs) was examined by five different paradigms: across a wideband of frequency, microstructure, input/output function, primary frequency ratio tuning curve, and group delay. The aim was to investigate the vulnerability of these different features to moderate levels of noise exposure. Nine subjects were exposed to third-octave-band noise. The DPOAE amplitude was reduced frequency specifically with the greatest reduction approximately half an octave above the frequency of the noise. The degree of amplitude reduction was greatest at low stimulus levels. There were no observed effects on the shape of the primary ratio tuning curve. A weak tendency to a decrease was seen in group delays. Distinct microstructure was seen in the amplitude against frequency of five out of seven subjects. The maximum to minimum ratio of the microstructure decreased, and the whole pattern shifted toward lower frequencies after noise exposure. Evidence of multiple internal reflection or interference was seen in the periodicity of the microstructure. Using a simple model of the microstructure based on multiple reflections, the noise-induced changes were reevaluated. A reduction in maximum to minimum microstructure ratio could be interpreted as a decrease in the internal reflection coefficient. The implications of these observations for the interpretation of the DPOAE measurements are considered. (C) 1996 Acoustical Society of America.