Abstract
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.
Highlights
Academic Editors: Gaetano Licitra, Environmental noise is everywhere
Active noise control uses traditional voice coil loudspeakers (VCLs) as the secondary source to suppress the noise in the target areas
It can be seen from the figure that when the parametric array loudspeaker (PAL) was used as the secondary source, the amplitude of the feedback path was obviously smaller than the secondary path
Summary
Academic Editors: Gaetano Licitra, Environmental noise is everywhere. when people work and live in a highnoise environment for a long time, it brings great risks to people’s health, such as hearing loss and noise trouble [1,2]. Active noise control uses traditional voice coil loudspeakers (VCLs) as the secondary source to suppress the noise in the target areas. There are still many shortcomings to using a traditional voice coil loudspeaker as a secondary source for noise control. In the above applications, the distance between the secondary source PAL and the noise reduction target is fixed and placed at a short distance, so it is impossible to adjust the distance of different targets adaptively. When the target is too close to the secondary source, this can cause sound field overflow and multiple harmonics to form superposition and interference with the other adjacent sound fields When it is too far, the noise reduction performance is greatly reduced.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
