The following link shows how to control and how to query the DF player, there are a couple of products calling themselves DF player but have slight differences so this link may not be exactly for your player. DFPlayer_Mini_SKU_DFR0299-DFRobot
As this disable stops internal clock in case of SD Card , it won't generate any small distortion type sound after we stop the player with command audio.disable();
In case of this DF Player a continue small level sound is present even after we simply stops the player
ans when connected to a PA system that small sound gets amplifies annoying people around