The antitragus is a small protrusion of firm flesh that is the main deflector of sound waves into the human ear. The opposing anterior tragus protrudes backward and is commonly manipulated with the pointed push of a finger to plug the ear canal and prevent sound from entering. Both are popular little knobs of the ear for piercing.
The external human ear, called the auricula, or pinna, has various protrusions and depressions surrounding the meatus, the auditory canal opening. Projecting backward over the meatus is a small triangular projection called the tragus, named for the Greek word for “goat” because of its resemblance to a goat’s beard with an under-surface tuft of hair. Opposing the tragus, almost as an overlapping flap to enclose the meatus, is a nearly identical tubercule, or wart-like projection, called the antitragus. The prominent gap separating the two is the intertragic notch. These and other features of the external ear have a firmness and elasticity because of tissue — mostly cartilage — that is connected to the head by ligaments and muscle.
Anatomically, the tragus and antitragus might appear to be enclosing lids of the ear canal. To block out noise, for example, some people cover the entire ear with their palm while others push the tragus with their index finger to shut the meatus closed. Audio devices, such as hearing aids and earphone buds, are either inserted into the meatus or nestled within the ear’s spherical depression called the concha, held in place by the pinching flaps of the tragus and antitragus. Functionally, the two flaps are funnels for sound waves to enter the ear canal.
The convoluted shape of the ear is purposeful in collecting and precisely deforming sound waves to enable the human brain to identify and locate its source. The audio technology named Dolby® uses this to its advantage, processing audio signals to mimic the changes that the ear’s contour would create, producing an audio illusion, for example, of sound that originates from behind the head. The tragus flap faces backward and collects sound waves from behind, and the opposing antitragus is the human ear’s main collector of sounds originating from directly ahead.
The tragus is not commonly pierced for jewelry, but antitragus piercing is very popular. Requires considerable force to penetrate the cartilage tissue because to its relative density, however, so the procedure is considered to be painful. It typically heals quickly, though, and rings, studs and barbells can be used used to adorn it.