Due to factors such as the propagation speed of the sound, there is a delay of one or two seconds between the sound returning to the singer's ear and the accompaniment heard by the audience. The monitor speakers allow the music accompaniment to be fed back to the singer or musician's ears in time. Let the singer's singing and the accompaniment be synchronized, so that the rhythm will not lag behind due to excessive delay.Monitor speakers are generally used on the stage for singers or band members to monitor their own singing or performance.