Active Hearing Protectors and Audibility of Critical Communications

描述（由申请人提供）：听力保护装置（HPD）的使用者，包括飞机空勤人员和地勤人员、军事人员和紧急响应人员以及在嘈杂环境中工作的工业、采矿和建筑人员通常佩戴的通信耳机和头盔，长期以来一直抱怨HPD干扰他们的通信能力和听到警告信号的能力。主动噪声控制技术与信号处理一起应用于HPD中内置的通信信道被提出作为一种潜在的解决方案。这种组合可以改善低频降噪，提高通信信道再现语音的清晰度，同时保持职业暴露要求内的总体降噪和HPD外警告声的感知。研究，以实现这些目标的基础上，提出了一种有源耳罩配备微型耳机和麦克风，和独立的频带的信号处理。该算法考虑了不同的信号处理复杂度，以优化语音信噪比，并降低掩蔽效应向上扩展的影响。通过建立基于主体（主观）和基于仪器（客观）的指标来确定主动和被动降噪、语音清晰度和警报声音感知（仅主观方法），从而预先证明“原理证明”。客观指标在主观测量所需时间的一小部分内提供近似结果，在器械开发期间用作相应主观指标的替代指标。 听力保护装置（HPD）的用户，包括通常由飞机空勤人员和地勤人员、军事人员和紧急响应人员以及在噪声环境中工作的工业、采矿和建筑人员佩戴的通信耳机和头盔，长期以来一直抱怨HPD干扰他们的通信和听到警告信号的能力。建议进行研究，以证明专门设计的专用HPD的“原理证明”：1）提高内置通信信道的语音清晰度; 2）保持HPD外部警报信号的感知; 3）保持环境噪声的衰减。

DESCRIPTION (provided by applicant): Users of hearing protection devices (HPDs), including the communication headsets and helmets commonly worn by aircraft air and ground crews, military personnel, and emergency responders, and persons in industry, mining and construction working in noisy environments, have long complained that HPDs interfere with their ability to communicate and to hear warning signals. The technology of active noise control together with signal processing applied to a communication channel built into the HPD is proposed as a potential solution. The combination could improve noise reduction at low frequencies and enhance the intelligibility of speech reproduced by the communication channel, while maintaining the overall noise reduction within occupational exposure requirements and the perception of an warning sound outside the HPD. Research to achieve these goals is proposed based on an active circumaural earmuff equipped with miniature earphones and microphones, and independent frequency bands of signal processing. Various levels of signal processing complexity are considered to optimize the speech signal-to-noise ratio, and reduce the influence of the upward spread of masking. The demonstration of "proof of principle" is preceeded by the establishment of subject based (subjective) and instrument based (objective) metrics for determining active and passive noise reduction, speech intelligibility, and the perception of warning sounds (subjective method only). The objective metrics, which provide approximate results in a fraction of the time required for subjective measurements, are to serve as surrogates for the corresponding subjective metrics during device development. Users of hearing protection devices (HPDs), including the communication headsets and helmets commonly worn by aircraft air and ground crews, military personnel, and emergency responders, and persons in industry, mining and construction working in noisy environments, have long complained that HPDs interfere with their ability to communicate and to hear warning signals. Research is proposed to demonstrate "proof of principle" of a specialized HPD designed specifically to: 1) improve speech intelligibility of a built-in communication channel; 2) maintain the perception of alarm signals external to the HPD, and; 3) maintain attenuation of environmental noise.