Graphic showing how ‘Audible enclaves’ work (IMAGE)
Caption
By positioning metasurfaces in front of two ultrasonic transducers, dual ultrasonic waves travel at two slightly different frequencies along a crescent-shaped trajectory until they intersect, forming an audible enclave where sound cab be heard. At other points along the trajectory, sound is not heard — meaning private listening is possible.
Credit
Provided by Heyonu Heo/Penn State
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Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted.
License
CC BY-NC-ND