Key Laboratory for Optoelectronic Technology and System of the Education Ministry of China, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China.
Int J Environ Res Public Health. 2021 Dec 27;19(1):269. doi: 10.3390/ijerph19010269.
Long-term exposure to environmental noise is dangerous to human health. Therefore, there is an urgent need to suppress or eliminate environmental noise. Due to the limitation of environmental space, the use of reverse sound waves emitted by loudspeakers for noise elimination has been widely used in noise control. However, because of the omni-directionality of sound propagation, a traditional voice coil loudspeaker (VCL) is used as a secondary source (emission reverse sound wave). It is easy to increase the sound pressure in non-target areas and form significant acoustic feedback to the reference source. Therefore, we propose an online secondary path modeling method using an adjustable parametric array loudspeaker (PAL) based on ultrasounds to eliminate environmental noise in real time. According to the different distance of the target, the size of the PAL is adjusted adaptively to realize the noise control of different long-distance targets. The distribution of quiet areas is discussed. The experimental results showed that a PAL as a secondary source had the same noise reduction effect as a traditional VCL, but it had longer propagation distance, smaller sound feedback and a more regular and controllable distribution of quiet areas. These research findings have great potential for improving environmental noise and creating a quiet environment.
长期暴露在环境噪声中对人类健康是有害的。因此，迫切需要抑制或消除环境噪声。由于环境空间的限制，使用扬声器发出的反向声波来消除噪声已被广泛应用于噪声控制中。然而，由于声音传播的全向性，传统的动圈式扬声器（VCL）作为二次声源（发射反向声波），很容易增加非目标区域的声压，并对参考声源形成显著的声反馈。因此，我们提出了一种基于超声波的可调参数阵列扬声器（PAL）的在线二次路径建模方法，用于实时消除环境噪声。根据目标的不同距离，自适应调整 PAL 的大小，以实现对不同远距离目标的噪声控制。讨论了安静区域的分布。实验结果表明，作为二次声源的 PAL 具有与传统 VCL 相同的降噪效果，但它具有更长的传播距离、更小的声反馈以及更规则和可控的安静区域分布。这些研究结果对于改善环境噪声和创造安静的环境具有很大的潜力。
