Because the audio cable in the factory. Not be available to cover all the points, this may cause.Mistakes in communication and therefore to avoid such problems, so let everyone do the following.
Due to the internal audio system in the plant. Can not be used to cover all the points. Can cause errors in communication. Therefore, to avoid such problems. Ask everyone to follow.
Because the sound system in the factory. Not available to cover all the points. May cause mistakes in communication. So, to avoid the occurrence of such problems. So everyone following .