Directional speakers have a small sound beam angle, which can effectively prevent close-range devices from interfering with each other; but the volume is not loud, suitable for 1-2 people in the area, with the effect of stereo headphone sound; large consumption, high material cost; but closer to actual exhibition hall use; good exhibition halls generally require quietness to prevent venting noise; but they also need automatic explanation services that do not affect others, which is suitable for this directional design solution;

Ultrasonic directional sound and ultrasonic directional speakers use directional sound technology to achieve precise explanations in small fixed areas, creating a novel explanation method of "one exhibit, one exclusive explanation point". Visitors do not need to wear any equipment. When they come to a specific area, they will be automatically sensed and recognized, and hear the directional explanation of the exhibits. When they leave, the sound will automatically stop. The sound starts when people come and stops when people leave. The explanation area and the non-explanation area are independent and do not affect each other.