Abstract: The acoustic controlled standing wave tube is composed of a transparent acrylic tube，a unit lighting array controlled by acoustic wave，a acoustic wave transducer and a hard end cover and holders. When the acoustic wave signals are provided to the acoustic wave transducer，the similar standing wave states are formed in the transparent acrylic tube due to the wave superposition. The theoretical analysis has shown that this standing wave has wave nodes and loops and is in agreement with that of the ideal standing wave. Therefore，this standing wave tube can be used to measure the wavelength of acoustic waves. With the acoustic controlled standing wave tube，by carefully adjusting the frequency and amplitude of the acoustic wave signals，the wave nodes and loops are able to be clearly displayed by the LED brightness. The experimental results have revealed that the measurement of acoustic velocity with such standing wave tube has advantages of accuracy and simplicity for operators.

Key words: the acoustic controlled standing wave tube, LED display, standing wave states, the acoustic velocity measurement