Behind-the-Ear (BTE) hearing aids hook over the top of the ear. Amplified sound is directed into the ear via a thin, clear plastic tube that is held in place by an earmold, which is custom-made to fit your ear. The BTE style is suitable for all types of hearing losses from mild to profound, and offers the maximum fitting flexibility. Many features, such as program push buttons and volume controls, are available. This style is exceptionally sturdy and reliable and less prone to damage from ear wax or moisture than the custom products. Battery life typically is longer because of the larger battery size. These aids can be connected to external sound sources, such as infrared listening systems and TVs.