One enduring challenge for controlling high frequency sound in local active noise control (ANC) systems is to obtain the acoustic signal at the specific location to be controlled. In some applications such as in ANC headrest systems, it is not practical to install error microphones in a person’s ears to provide the user a quiet or optimally acoustically controlled environment. Many virtual error sensing approaches have been proposed to estimate the acoustic signal remotely with the current state-of-the-art method using an array of four microphones and a head tracking system to yield sound reduction up to 1 kHz for a single sound source. In the work reported in this paper, a novel approach of incorporating remote acoustic sensing using a laser Doppler vibrometer into an ANC headrest system is investigated. In this “virtual ANC headphone” system, a lightweight retro-reflective membrane pick-up is mounted in each synthetic ear of a head and torso simulator to determine the sound in the ear in real-time with minimal invasiveness. The membrane design and the effects of its location on the system performance are explored, the noise spectra in the ears without and with ANC for a variety of relevant primary sound fields are reported, and the performance of the system during head movements is demonstrated. The test results show that at least 10 dB sound attenuation can be realised in the ears over an extended frequency range (from 500 Hz to 6 kHz) under a complex sound field and for several common types of synthesised environmental noise, even in the presence of head motion.

在本地有源噪声控制（ANC）系统中控制高频声音的一项持久挑战是在要控制的特定位置获得声音信号。在某些应用中，例如在ANC头枕系统中，将误差麦克风安装在人耳中为用户提供安静或最佳的声学控制环境是不切实际的。已经提出了许多虚拟错误感测方法，以使用四个麦克风阵列和头部跟踪系统的当前最新方法，远程估计声信号，从而对单个声源产生高达1 kHz的声音衰减。在本文报道的工作中，研究了一种使用激光多普勒振动计将远程声音感应整合到ANC头枕系统中的新颖方法。在这个“虚拟ANC耳机”系统中，轻巧的逆反射膜拾音器安装在头部和躯干模拟器的每个合成耳朵中，以最小的侵入性实时确定耳朵中的声音。探索了膜的设计及其位置对系统性能的影响，报告了在不使用和使用ANC的情况下针对各种相关主要声场的耳朵中的噪声频谱，并演示了系统在头部运动过程中的性能。测试结果表明，在复杂的声场和几种常见类型的合成环境噪声下，即使存在以下情况，在扩展的频率范围（500 Hz至6 kHz）中，耳朵也可以实现至少10 dB的声音衰减：头部运动。