This paper explores the development of thin panels that can be controlled electronically so
as to provide surfaces with desired reflection coefficients. Such panels can be used as either …

Low-frequency reverberant sound fields are usually suppressed by means of either adaptive
feedforward control or Helmholtz resonator. Feedforward systems utilize a noise reference …

A new type of acoustic liner developed for broadband noise reduction in flow ducts is
considered in this paper. It combines passive absorbent properties of a porous layer and …

A practical engineering noise control measure that can often be used for plate-like structures
is to construct them from perforates. This can dramatically reduce the sound radiation from …

In a narrow sense, coherent active control of sound and vibration is the cancellation or (less
often) enhancement by superposition of an antiphase or in-phase additional signal, usually …

A method to attenuate the global acoustic pressure of low-frequency harmonic acoustic
disturbances in the interior of a small aircraft cabin mockup is proposed herein. This method …

New miniaturization and integration capabilities available from emerging
microelectromechanical system (MEMS) technology will allow silicon-based artificial skins …

Noise control and source design require the measurement of sound radiation at low
frequencies. Anechoic rooms, which are designed for this purpose, allow echo-free …

A hybrid electro-acoustic nonlinear membrane absorber working as a nonlinear energy sink
(here after named EA-NES) is described. The device is composed of a thin circular visco …

The sound quality in a room is of fundamental importance for both recording and
reproducing processes. Because of the room modes, the distributions in space and …