HEARING HAZARD ASSOCIATED WITH INDUSTRIAL NOISE EXPOSURE

许多工业噪声环境的特点是高水平的 叠加在连续背景噪声上的撞击噪声 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，其中许多 “复杂的噪音”环境造成听力损失的风险异常之高。 反复暴露的个体。需要开发以下指标： 可以从这样的“复杂噪声”环境中提取并用于 客观地估计这种环境对听力造成的危害。 这项提议就是针对这样一个目标的。具体来说，我们建议：(1) 设计了一种模型数字噪声产生系统，可用于 再现高层次“复合型”产业的本质特征 噪音环境。该系统将整合多个功能，例如 冲击源和房间反射特性产生的“复合体” “高斯型”和“非高斯型”分量可控的噪声； (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 利用频域自适应噪声消除的方法 峰度和倒谱分析；(3)启动一系列动物暴露 使用“复杂噪声”范例的实验，旨在探索 复杂噪声环境的哪些指标适合预测 长期暴露对听力的危害。这样做的理由是 与“复合体”相关的听力危害的研究方法 噪声“环境取决于：(1)我们的经验是，参数 过去在我们的实验室和大多数其他实验室使用的方法 实验室需要异常大量的动物暴露和 一项非常耗时的努力来理解相互之间的关系 在与高水平冲击噪声有关的许多变量中；(2)a 认识到这种参数方法的结果，虽然他们有 在某些层面的调查中非常有启发性和有效性，很难 适用于真实的工业噪声环境，其中时间信号 即使使用复杂的仪器也很难进行评估 而且不可能使用许多可用的常规噪声进行评估 测量设备。我们的方法将产生一个通用的方法论 可用于建模和评估工业噪声环境和货舱 承诺产生可用来衡量危险的指标 几乎由任何工业噪声环境构成。

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.