Optimizing multi-user indoor sound communications with acoustic reconfigurable metasurfaces

Area of Science:

• Acoustics
• Wave physics
• Metamaterials

Background:

• Indoor sound propagation is complex due to wave scattering, leading to crosstalk in acoustic communication systems.
• Existing methods struggle to effectively isolate multiple sound sources and receivers in reverberant environments.

Purpose of the Study:

• To demonstrate the isolation of acoustic communication channels in a room using wavefield shaping.
• To achieve maximal Shannon capacity and minimal crosstalk simultaneously in indoor acoustic environments.

Main Methods:

• Utilized acoustic reconfigurable metasurfaces (ARMs) with 200 switchable units for controlled phase shifts (0 or π) of reflected sound waves.
• Employed optimization protocols based on communication theories to actively reshape the sound wavefield.
• Experimentally validated functionalities over a broad frequency spectrum, exceeding the room's coherence bandwidth.

Main Results:

• Successfully isolated acoustic communication channels, significantly reducing crosstalk between multiple sources and receivers.
• Achieved diverse acoustic functionalities, including multi-channel and multi-spectral channel isolations.
• Demonstrated frequency-multiplexed acoustic communication, showcasing enhanced data transmission capabilities.

Conclusions:

• Wavefield shaping with ARMs offers a novel and effective strategy for controlling sound propagation in complex indoor spaces.
• This approach provides new avenues for advanced acoustic engineering and high-performance acoustic communication systems.