Extraordinary sound screening in perforated plates

TL;DR

This paper demonstrates extraordinary sound transmission and screening effects in perforated plates, revealing unique acoustic phenomena near the array's period, influenced by hole distribution randomness and impedance contrast.

Contribution

It provides experimental and theoretical evidence of enhanced sound transmission and screening in perforated plates, highlighting effects beyond traditional mass law predictions.

Findings

Nearly full transmission at resonant frequencies

Sound screening exceeds mass law predictions

Random hole distribution influences acoustic behavior

Abstract

We report extraordinary effects in the transmission of sound through periodically perforated plates, supported by both measurements and theory. In agreement with recent observations in slit arrays [M. H. Lu et al. Phys. Rev. Lett. 99, 174301 (2007)], nearly full transmission is observed at certain resonant frequencies, pointing out at similarities of the acoustic phenomena and their optical counterpart. However, acoustic screening well beyond that predicted by the mass law is achieved over a wide range of wavelengths in the vicinity of the period of the array, resulting in fundamentally unique behavior of the sound as compared to light. The randomness of the hole distribution and the impedance contrast between the fluid and the solid plate are found to play a crucial role.