Toph Beifong is an earthbending master, one of the most powerful of her time, and the discoverer of metalbending. Blind since birth, Toph was constantly treated condescendingly because of her visual impairment, particularly by her overprotective parents, Lao and Poppy Beifong. Upon discovering badgermoles, earthbending animals who are also blind, she learned how to use earthbending as an extension of her senses. This gave her the ability to "see" every vibration that passes through the ground.

voice example:https://www.youtube.com/watch?v=D7E-D1KvXxE