NEW HEARING PROTECTOR ATTENUATION MEASUREMENT METHOD

听力保护装置提供的保护（衰减）程度 （HPD），如耳塞，耳罩和耳道帽，通常要少得多 在实际使用中比在实验室认证测试中， 评级是基于。此外，衰减在 个人，提供给任何特定的保护金额 个人几乎完全未知。因此，保护不足 暴露在高噪音水平下的工人通常只能通过 随后测量他们的听力损失。这些程序可以随时 用于评估HPD的现场性能， 工人培训和听力保护计划评估。所述一 目前使用的方法仅适用于耳塞，显示出相当大的 与标准方法的差异，必须在安静的情况下进行 听力测试室的环境。 提出了一种测量HPD衰减的新方法， 在中等噪音的环境中进行，可用于任何类型的 听力保护器或HPD组合。这是一个响度平衡 一种技术，其中一个声音通过骨头传递到内耳- 传导换能器，并且另一声音从外部传递到耳朵 和火奴鲁鲁警局通过平衡两种声音的响度， 在没有HPD的情况下，可以直接计算HPD的衰减。 初步结果表明，这是一种可重复的技术， 给出了与标准方法相当的测量结果。 拟议的研究旨在制定程序， 使用这种新技术作为替代方法所需的仪器 HPD衰减测量方法。该方法还将与 实验室和现场测量的常用程序。 将使用该程序评价各种不同类型的HPD 以证明其在实际实践中的有用性，并提供 关于该方法的任何缺陷和局限性的信息。

The degree of protection (attenuation) given by hearing protection devices (HPDs) such as earplugs, earmuffs, and canal caps is generally much less in actual use than in laboratory certification tests upon which HPD ratings are based. Also, the attenuation varies so greatly between individuals that the amount of protection provided to any particular individual is almost completely unknown. As a result, underprotection of workers exposed to high noise levels can often only be detected by subsequent measurement of their hearing loss. Procedures which can readily be used to assess field performance of HPDs would be very useful for worker training and hearing conservation program assessment. The one method currently in use is only applicable to earplugs, shows considerable variance from the standard method, and must be done in the quiet environment of an audiometric test booth. A new procedure for measuring HPD attenuation is proposed which may be done in moderately noisy environments and could be used for any sort of hearing protector or combination of HPDs. It is a loudness balance technique in which one sound is delivered to the inner ear by a bone- conduction transducer and another sound is delivered externally to the ear and the HPD. By balancing the loudness of the two sounds both with and without the HPD, the attenuation of the HPD may be directly calculated. Preliminary results indicate that it is a reproducible technique which gives measurements comparable to the standard methods. The proposed research is intended to develop procedures and instrumentation necessary to use this new technique as an alternative method of HPD attenuation measurement. The method will also be compared to the commonly used procedures for both laboratory and field measurements. A variety of different types of HPD will be evaluated using the procedure to demonstrate its usefulness in actual practice and to provide information on any defects and limitations of the method.