In order to improve and broaden the sound absorption performance of porous materials with
low flow resistance, this study proposes the composite meta-porous structure embedded …

Nowadays the use of porous polyurethane sponge (PPS) is very common for sound
absorption, thanks to its light-weight feature and easy fabrication. However, in many …

Submerged systems are found in many engineering, biological, and medicinal applications.
For such systems, due to the particular environmental conditions and working medium, the …

This work investigates a porous composite with modifiable micro-geometry so that its ability
to absorb noise can be accommodated to different frequency ranges. The polymeric …

In this paper, a new hybrid passive-active sound absorption method is investigated, in which
porous materials and a loudspeaker are parallelly combined so that sound absorption over …

Active acoustic insulation systems tend to suffer from narrow insulation frequency bandwidth
and low-frequency deficiencies. In this paper, we employed a quasi-zero stiffness supported …

Piezoelectric shunt damping technology has been applied in the field of underwater sound
absorption in recent years. In order to achieve broadband echo reduction, semi-active …

Boundary treatment for noise mitigation has long been targeted by both passive and active
noise control strategies. Applications range from building and vehicle sound comfort, to the …

Different hybrid active–passive absorbers have been developed at the LMFA that seem well
suited for the use as turboengine nacelle liners. The basic version is made of a resistive …

This paper is dedicated to an experimental implementation of active anechoicity control
illustrating previous theoretical work. The aim of this experimental is to cancel the pressure …