HKU Engineers Find Physics Principle That Breaks Sound Absorption Limits

Generalized causality constraint based on duality symmetry reveals untapped potential of sound absorption - Nature Communications

Causality constraints are known to bind sound absorption to a limit that can only be achieved by optimizing the system bandwidth for a specific material thickness. This limit is defined on the assumption of a one-port system, generally causing duality symmetry to be overlooked. Here, we define a generalized causality constraint of sound absorption by investigating reflection and transmission of a two-port hybrid monopole-dipole resonator. With o…

HKU Engineers Discover New Physics Principle to Break Sound Absorption Barriers in Ventilated Spaces - All News

Figure 1: The research team from The University of Hong Kong presented their findings at the Phononics 2025: 7th International Conference on Phononic Crystals/Metamaterials, Phonon Transport, Topologi...

Generalized causality constraint based on duality symmetry reveals untapped potential of sound absorption

Causality constraints are known to bind sound absorption to a limit that can only be achieved by optimizing the system bandwidth for a specific material thickness. This limit is defined on the assumption of a one-port system, generally causing duality symmetry to be overlooked. Here, we define a gen …

Ventilated Sound Absorption: New Material Breaks Noise Reduction Limits – Archyde

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New Physics Breaks Sound Absorption Barriers

Figure 1: The research team from The University of Hong Kong presented their findings at the Phononics 2025: 7th International Conference on Phononic