Behind-the-ear (BTE) hearing aids, the battery compartment, microphone, and controls sit behind the ear with a clear tube connecting to the ear mould. Because the ear mold can be easily changed without having to purchase a new hearing aid, this style is often chosen for children whose ear moulds need to be changed as they grow. The casing that sits behind the ear can be purchased in various colors to match the wearer’s skin tone, hair color, or fashion choice. The BTE is for those with mild to profound hearing loss.