Graphene is called "magic material" - the thinnest, hardest, least resistive material ever! The sound of the earphones coming into the ear is the vibration from the internal horn diaphragm, while the Graphene toughness can keep it in shape. As the diaphragm does not change during the vibration process, it reduce the sound distortion which makes the sound being clearer and the sound field wider!
Besides, this material is light enough to make the audio response being more sensitive. The vibration efficiency is improved, and less energy can be promoted!