A" Speaker, fires directional specific sound "like a laser" using ultrasonic technology. 300% funded in 48h. : r/shittykickstarters
Parametric Speaker Test - YouTube
Near-field characteristics of the parametric loudspeaker using ultrasonic transducers - ScienceDirect
Holographic Whisper: Rendering audible sound spots in three-dimensional space by focusing ultrasonic waves
Parametric sound - Ultrasound Research Group
Amazon.com: ELTEM/PROPA-U100 / Directional Loudspeaker, Directional Speaker, Ultrasonic Speaker, Directional Sound System for Museums, Exhibits, Art Gallery and Digital Signage – Black : Everything Else