Article
Acoustic Metamaterial for Absorption of Acoustic Leakage in Circumaural Headphones (en)
* Presenting author
Abstract:
We are presenting a study of an acoustic metamaterial for the earpad of closed-back headphones that increases the acoustic insulation from the external sound field. More specifically, it attenuates acoustic leakage due to parasitic channels as they can occur between the earpad and the user's head. The entirely passive metamaterial is based on an array of identical acoustic masses coupling to a common compliance, where the mass channels are located in the face of the earpad that sits against the user's head. When the headphones are worn as intended, the metamaterial lies dormant inside the earpad and is not active. But when an acoustic leakage occurs, the metamaterial becomes active and attenuates the transmission on the leak channel. The frequency range of the effect is optimised to address the region where active noise control systems are less effective. In a proof-of-concept, we demonstrate an effect as intended over a frequency range spanning one decade. The result are discussed and the prototype for the next steps is presented.