Active Hearing Protectors and Audibility of Critical Communications

描述(申请人提供)：听力保护设备(HPD)的用户，包括飞机空中和地勤人员、军事人员和应急人员以及在嘈杂环境中工作的工业、采矿和建筑业人员通常佩戴的通信耳机和头盔，长期以来一直抱怨HPD干扰他们的通信和听到警告信号的能力。将有源噪声控制技术与信号处理技术相结合应用于HPD中的通信通道是一种潜在的解决方案。两者的结合可以改善低频率的降噪效果，并提高通信渠道重现的语音的清晰度，同时保持整体降噪效果，使其符合职业暴露要求，并能在HPD之外感知到警告声音。为了实现这些目标，提出了一种基于配备微型耳机和麦克风的有源环绕耳罩以及独立的信号处理频段的研究。该算法综合考虑了不同程度的信号处理复杂度，优化了语音的信噪比，减小了掩蔽向上扩散的影响。在“原则证明”的论证之前，建立了基于主体(主观)和基于仪器(客观)的衡量标准，用于确定主动和被动降噪、语音清晰度和对警告声音的感知(仅限于主观方法)。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，在设备开发期间用作相应的主观指标的替代品。听力保护设备(HPD)的用户，包括飞机空中和地勤人员、军事人员和应急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干扰他们的通信和听到警告信号的能力。有人建议进行研究，以证明专门设计的HPD的“原则证明”：1)提高内置通信通道的语音清晰度；2)保持对HPD外部报警信号的感知；以及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.