3D-printed speaker cover can focus audio into a private 'sound spot'

Music lovers may one day be able to blast their favorite artists, headphone-free, without angering the neighborhood or colleagues, thanks to researchers at Penn State. The team designed a system that can manipulate sound waves so that they are only audible at a precise spot slightly wider than an inch. Despite this tiny focal point, their system can produce high-quality audio, potentially offering listeners a crisp, yet private, sound experience. The team detailed their work in a paper recently published in IEEE Transactions on Ultrasonics.