Air transparent soundproof window

TL;DR

This paper introduces a novel air-transparent soundproof window utilizing diffraction and acoustic metamaterials, achieving significant sound attenuation across a broad frequency range through a resonator array design.

Contribution

It presents a new design of soundproof window based on diffraction and acoustic metamaterials, demonstrating effective sound attenuation with air-transparency.

Findings

Sound level reduced by 30-35dB with 20mm holes

Sound level reduced by 20-35dB with 50mm holes

Effective negative modulus achieved through geometric factors

Abstract

A soundproof window or wall which is transparent to airflow is presented. The design is based on two wave theories of diffraction and acoustic metamaterials. It consists of a three-dimensional array of strong diffraction-type resonators with many holes centered at each individual resonator. The acoustic performance levels of two soundproof windows with air holes of $20mm$ and $50mm$ diameters were measured. Sound waves of 80dB in the frequency range of $400 - 5,000Hz$ were applied to the windows. It was observed that the sound level was reduced by about $30 - 35$dB in the above frequency range with the $20mm$ window and by about $20 - 35$dB in the frequency range of $700 - 2,200Hz$ with the $50mm$ window. It is an extraordinary acoustic anti-transmission. The geometric factors which produced the effective negative modulus were obtained.