Designed as part of a project hosted by Bang & Olufsen, the Klang speakers use a satellite dish design and sound physics to focus the beam to one specific point. As Dvice points out, the soundwave is above the threshold of human hearing range, but ultrasonic waves split in three, producing an audible wave encapsulated by two inaudible ones. Sound is only noticeable when it hits an obstruction. And because of this, the left ear can only hear sound coming from the left speaker and the right ear can only hear sound from the right speaker, creating an intense stereo experience.
But what does this mean for you, the user? Well, if these speakers were more than a prototype, you could enjoy porn and/or Justin Bieber as loud as you want without your parents and/or roommates ever knowing. Obviously.