Imaging Systems and Audio Control Utilizing Acoustics

Abstract

Conventional noise reduction materials such as concrete, wood, foam, and glass are widely used in buildings to minimize environmental noise. However, these materials have limited effectiveness in reducing low-frequency noise. Acoustic metamaterials have been introduced as a more efficient alternative, offering superior low-frequency sound reduction while being lighter and more cost-effective than traditional bulky materials. This study investigates the feasibility of acoustic metamaterials for noise reduction. Five acoustic enclosure samples were fabricated using different materials, each with dimensions of 100 mm³. The wood enclosure was manually constructed, while acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), PLA with a 1 mm-thick metamaterial layer, and PLA with a 5 mm-thick metamaterial layer were produced using three-dimensional (3D) printing. The performance of these enclosures was evaluated based on the decibel (dB) drop, measuring the difference in sound pressure levels before and after placing the enclosure over the sound source. Among all samples, the PLA enclosure with a 5 mm-thick metamaterial layer demonstrated the highest noise reduction, achieving a maximum sound pressure level reduction of 26.1 dB at 800 Hz. This result confirms that increasing the metamaterial thickness enhances sound reduction performance.