Development of a personalized acoustic reproduction system using evanescent waves

In recent years, the demand for private acoustic environments has grown rapidly in enclosed spaces such as vehicle cabins and offices. To address this, we propose a novel approach for generating evanescent waves using hydrodynamic short-circuiting, enabling compact and high-performance personalized sound reproduction. Unlike conventional methods that rely on large-scale phase velocity control, our system utilizes a simple flat plate structure with multiple actuators and multi-point control to induce spatial vibration modes that confine sound energy near the source. Theoretical modeling and experimental validation demonstrate that the proposed system achieves exponential attenuation of sound pressure in the propagation direction, consistent with evanescent wave characteristics. Measurements show significant suppression of sound dispersion and effective localization of acoustic energy. Our approach offers a scalable and integrable solution for personalized audio delivery in various applications, including automotive, aerospace, office, and home environments. By minimizing sound leakage and enhancing spatial control, this technology holds promise for next-generation acoustic systems tailored to individual needs.