The wall chart plays a particularly important role in early childhood education, and it is particularly simple to operate, combined with pictures and texts, and easy to remember. If there is no sound in the children's wall chart, first check whether the switch is turned on and adjust the volume appropriately. Secondly, it may be that the battery cannot be used for a long time. It is necessary to replace or recharge the battery in time. If it still doesn't work, you need to buy a new one.