HEARING HAZARD ASSOCIATED WITH INDUSTRIAL NOISE EXPOSURE

许多工业噪声环境的特征是高水平的 叠加在连续背景噪声上冲击噪声 产生非常复杂的时间信号。有限的人口统计数据和 越来越多的实验动物数据表明， “复杂的噪音”环境对听力损失造成了异常高的风险， 反复暴露的个体。需要制定衡量标准， 可以从这样的“复杂噪声”环境中提取， 客观地估计这些环境对听力造成的危害。 本提案就是针对这一目标提出的。具体而言，我们建议：（1） 设计了一种数字噪声发生系统模型， 再现高层次“复合型”产业的本质特征 噪音环境。该系统将包括多个功能， 影响光源和房间反射特性，产生“复杂” 可以控制“高斯”和“非高斯”成分的噪声; (2)探索新的信号分析方法的适用性， 可用于定量评估非高斯噪声环境， 听力保护的目的。主要注意力将集中在 利用自适应噪声消除的方法、频域 峰度和倒谱分析;（3）启动一系列动物暴露 使用“复杂噪音”范例的实验旨在探索 “复杂噪声”环境的哪些度量是 长时间暴露对听力的危害。这种做法的理由是， 听力损害的研究方法 噪声”环境依赖于：（1）我们的经验，参数 过去在我们的实验室和大多数其他国家使用的方法 实验室需要大量的动物接触， 这是一项非常耗时的工作， 在与高水平撞击噪音有关的众多变量中;（2）a 认识到这种参数方法的结果，虽然它们具有 在某些层面上的调查是非常有启发性和有效的，很难 适用于实际的工业噪声环境，其中时间信号 即使使用复杂的仪器也很难评估 并且不可能使用大部分可用的常规噪声来评估 测量设备我们的方法将产生一个通用的方法， 可用于模拟和评估工业噪声环境和保持 产生可用于衡量危险的指标的承诺 几乎任何工业噪音环境都能造成这种影响。

Many industrial noise environments are characterized by high levels of impact noise that are superimposed on a continuous background noise thus producing a very complex temporal signal. The limited demographic data and an increasing body of experimental animal data show that many of these "complex noise" environments pose an unusually high risk of hearing loss to the repeatedly exposed individual. The need exists to develop metrics which can be extracted from such "complex noise" environments and used to objectively estimate the hazards that such environments pose to hearing. This proposal is directed toward such a goal. Specifically we propose: (1) to design a model digital noise generation system which can be used to reproduce the essential characteristics of high level "complex" industrial noise environments. The system will incorporate features such as multiple impact sources and room reflection characteristics to produce "complex" noises whose "Gaussian" and "non-Gaussian" components can be controlled; (2) to explore the applicability of new approaches to signal analysis that can be used to quantitatively evaluate non-Gaussian noise environments for the purpose of hearing conservation. Primary attention will focus upon methods which utilize adaptive noise cancellation, frequency domain kurtosis and cepstral analysis; (3) to initiate a series of animal exposure experiments using "complex noise" paradigms that are designed to explore which metrics of a "complex noise" environment are suitable predictors of the hazard to hearing following prolonged exposures. The rationale of this approach to the study of the hearing hazards associated with "complex noise" environments rests upon: (1) our experience that the parametric approach used in the past in our laboratories and in most other laboratories requires an inordinately large number of animal exposures and an extraordinary time consuming effort to understand the interrelations among the many variables associated with high level impact noise; (2) a recognition that the results of such a parametric approach, while they have been very instructive and valid at some levels of inquiry, are difficult to apply to realistic industrial noise environments where the temporal signals can be very difficult to evaluate even using sophisticated instrumentation and impossible to evaluate using much of the available conventional noise measuring equipment. Our approach will yield a generalized methodology that can be used to model and evaluate industrial noise environments and holds the promise for producing metrics that can be used to gauge the hazards posed by virtually any industrial noise environment.