The French startup company Akoustic Arts has developed a directional loudspeaker that can send a focused sound beam to a single person, with other people in the vicinity not hearing it. An Indiegogo campaign to finance the project is currently running, and with more than four times the target amount already subscribed, it is highly successful.
 
The directional speaker, dubbed “A”, consists of an array of ultrasonic transducers. With this arrangement, a highly focused sound beam can be generated by using the audio signal to modulate the ultrasonic signals from the transducers. The speaker will be available in two sizes: A and A Junior. The larger model, which has a better directional effect, has 200 transducers; the smaller model has 37. Both models have a frequency bandwidth of 60 Hz to 20 kHz. The directional effect does not come cheap: the Junior model is priced at USD 350, and its bigger cousin is priced at USD 550.
 
Elektor Magazine previously discussed this topic in a construction project. If you want to learn more about it, have a look at the “Ultrasonic Directive Speaker” article in the March 2011 issue and try it for yourself.