Omnidirectional Ventilated Acoustic Barrier

TL;DR

This paper introduces an omnidirectional acoustic barrier with subwavelength thickness that effectively blocks low-frequency sound from all directions while maintaining high ventilation, achieved through a novel interference-based design.

Contribution

It presents a new design of a thin, ventilated acoustic barrier utilizing Fano-like interference, combining simplicity in fabrication with effective sound insulation and airflow.

Findings

Blocks low-frequency sound from all directions

Allows 63% air flow through the barrier

Matches simulated results with experimental measurements

Abstract

As an important problem in acoustics, sound insulation finds applications in a great variety of situations. In the existing schemes, however, there has always been a tradeoff between the thinness of sound-insulating devices and their ventilating capabilities, limiting their potentials in the control of low-frequency sound in high ventilation environments. Here we design and experimentally implement an omnidirectional acoustic barrier with planar profile, subwavelength thickness (0.18lambda) yet high ventilation. The proposed mechanism is based on the interference between the resonant scattering of discrete states and the background scattering of continuous states that induces Fano-like asymmetric transmission profile. Benefitting from the binarystructured design of coiled unit and hollow pipe, it maximally simplifies the design and fabrication while ensuring the ventilation for all the non resonant units with open tubes. The simulated and measured results agree well, showing the effectiveness of our proposed mechanism to block low frequency sound coming from various directions while allowing 63% of the air flow to pass. We anticipate our design to open routes to design sound insulators and to enable applications in traditionally unattainable cases such as those calling for noise reduction and cooling simultaneously.