The tragus is the pointed flap on the external ear that covers the concha, the rounded bowl that forms the back of the ear. The name of this part of the ear actually comes from the Greek word tragos. In Greek, this means "goat," and refers to the look of the goat's tuft of hair.
The primary function of the tragus is to help one differentiate sounds coming from behind from sounds that are in front of the body. This part of the external ear is effective because it does not face forward. On the contrary, the front of this part of the ear faces toward the back of the head. This allows the tragus to pick up noise from behind. The brain, in turn, is able to distinguish those sounds from others based on the delay that passes when hearing them.
While the primary evolutionary function of this pointed ear flap is essential to hearing, some modern conveniences and trends depend upon it. The tragus can serves a number of purposes in contemporary society. For instance, ear buds, a popular type of earphone used with personal music players, rely on the tragus to hold them in place.
Another use of the tragus is to protect the opening of the ear or the concha from loud noises. While some people put their fingers into or cover their ears to shield themselves from loud noises, others use the tragus as a protective flap. This is done by using the index finger to push the flap over the opening of the ear, muting exterior sound.
Some some communities, people choose to use the tragus for personal ornamentation by piercing it. This kind of piercing occurs when a tiny hole is punched through the flap so that earrings may be hung from it. Because there are not many nerves in this flap over the ear, some claim that the piercing is not very painful, though some have reported that they experienced sharp pain which may last for a minute or more.
In some cases, piercings can lead to tragal infections. These occur often when the earring is taken out before the piercing has healed. When this is the case, subjects report that there is swelling on the tragus, followed by the presence of a red bump. Many also report redness and in some cases further discoloration. Since these infections can only enter the body through an open wound or pierced skin, infections in this part of the external ear are more common among those who have had piercings or injuries.