快科技4月6日消息，在一項發表於《美國國家科學院院刊》的最新研究中，A research team led by acoustics professor Yun Jing has succeeded in creating an "audible closed sound zone" that achieves the magical effect that only a specific individual can hear.

Using two ultrasonic transducers paired with acoustic metasurfaces, the researchers emitted two nonlinear ultrasonic beams that bend themselves and eventually intersect at a certain point.

Only those who stand at this intersection can hear the sound, and the people around them can't hear it at all even if they stand in front of the sound source, as if turning the magic of "transmitting sound into secret" in martial arts novels into reality.

The two ultrasonic beams are inherently silent, and only when they intersect do they produce local, nonlinear interactions, resulting in audible sound.

The research team tested the system in a normal room and showed that the system could function even in complex environments where sound was reflected multiple times.

This shows that the technology is not only suitable for quiet indoor environments, but can also be useful in classrooms, vehicles, and even outdoors, where people in the "audible enclosed sound zone" feel like they are wearing a pair of virtual headphones and can hear their own audio content.

At present, researchers have successfully transmitted 60 decibels of sound to specific individuals in the range of 0 meters, and if the intensity of ultrasound is further increased, the transmission distance and volume are expected to be improved.