It may someday be possible to listen to a favorite podcast or song without disturbing the people around you, even without wearing headphones. In a new advancement in audio engineering, a team of researchers led by Yun Jing, professor of acoustics in the Penn State College of Engineering, has precisely narrowed where sound is perceived by creating localized pockets of sound zones, called audible enclaves. In an enclave, a listener can hear sound, while others standing nearby cannot, even if the people are in an enclosed space, like a vehicle, or standing directly in front of the audio source.
In a study published today (March 17) in the Proceedings of the National Academy of Sciences, the researchers explained how emitting two nonlinear ultrasonic beams create audible enclaves, where sound can only be perceived at the precise intersection point of two ultrasonic beams.
"We use two ultrasound transducers paired with an acoustic metasurface, which emit self-bending beams that intersect at a certain point," said corresponding author Jing. "The person standing at that point can hear sound, while anyone standing nearby would not. This creates a privacy barrier between people for private listening."
