1º_ It is a sense present in most animals that allows to perceive the sounds. 2º_ It is also the organ that converts sounds into nerve impulses for the brain to interpret. They are usually two, located on the head, and look like holes surrounded by one ear. 3º_ By the previous one, it is called 'ear' to holes with different uses in mechanisms and structures. 4º_ As an adjective it is said of what is perceived with the sense of hearing. 5º_ Participle of the verb to hear . Watch listen, headset.
