Archive: https://archive.today/ldji6 From the post: >>The loudspeaker on your home entertainment equipment is designed to project audio around the space in which it operates, if it’s not omnidirectional as such it can feel that way as the surroundings reflect the sound to you wherever you are. Making a directional speaker to project sound over a long distance is considerably more difficult than making one similar to your home speaker, and [Orange_Murker] is here with a solution. At the recent Hacker Hotel conference in the Netherlands, she presented an ultrasonic parametric speaker. It projects an extremely narrow beam of sound over a significant distance, but it’s not an audio frequency speaker at all.