It is a speaker that direct the sound to a specific direction so that others who are in its path do not hear anything.
In some cases, we cannot use regular speakers due to noise pollution as they transfer sound spherically through air molecular vibrations. Directional sound systems are used to avoid noise pollution and send the sound to a specific individual. In this way, the sound travels faster and directly goes to an audience in a linear and direct way instead of spreading out in the environment in circular waves. As a result, only those individuals who are in its limited range can hear the voice without others noticing it. In other words, sound like laser light moves in a limited range and is audible exclusively in the direction of sound motion. The range of speaker array in a prepared sample is up to 50 meters while divergence range is less than 10 degrees.