What is the ear?
The human ear is an organ that combines two functions: the sense of hearing and the sense of balance.
The ear anatomy
The ear is divided into three anatomical regions:
The outer ear.
This includes the pinna (auricle auris), the external auditory canal (meatus acusticus externus) and the eardrum (membrana tympani).
The auricle
You can learn more about it in the article Auricle.
The external auditory canal (meatus acusticus externus) consists of a cartilaginous section at the beginning, which then turns into a bony section. It is about three to three and a half centimeters long overall, half a centimeter wide, and slightly curved. The skin of the ear canal contains hair follicles, sebaceous glands and sweat glands. The latter secrete earwax (cerumen). This sticky, yellowish secretion cleans the ear canal and prevents the penetration of water, dust and dirt.
The eardrum (membrana tympani) is a membrane that separates the ear canal from the middle ear. It is about 0.1 millimeter thick and nine to eleven millimeters in diameter. The tympanic membrane is grayish white, usually transparent, and under tension. It is not completely flat because the first ossicle, the malleus on the side of the middle ear, is fused to the center of the eardrum membrane and gives it its shape.
The middle ear
The ossicles
You can find out everything you need to know about the three tiny, movable bones that are important for sound transmission (hammer, anvil and stirrup) in the article Ossicles.
Eustachian tube
From the middle ear there is a connection to the pharynx, called the Eustachian tube (Tuba auditiva). You can read more about it in the article Eustachian tube.
The inner ear (labyrinth)
This is where the actual organ of hearing (organ of Corti) and the organ of balance are located. You can read everything important about the hearing organ in the article Inner ear.
Organ of balance
You can find out everything important about how the sense of balance works and how dizziness can occur in the article Organ of balance.
What is the function of the ear?
The functions of the ear are hearing, i.e. auditory perception, and the sense of balance – without these functions, humans would not be able to perceive tones, sounds and noises and would constantly feel dizzy.
Auditory perception
You can read about how sound is picked up, passed on by the ossicles and conducted to the sensory cells in the form of a traveling wave in the fluid-filled inner ear in the article Auditory Perception.
Where is the ear located?
What problems can cause the ear?
Inflammation of the external auditory canal (for example, an abscess or boil) is called otitis externa. It causes pain and itching in the external auditory canal. The cause of the inflammation of the ear canal is often bacteria, which can be “caught” especially when swimming. Doctors therefore also speak of bathing otitis.
An inflammation of the middle ear (otitis media) usually develops as a result of a cold or a sore throat, when the pathogens ascend via the Eustachian tube. Children are particularly susceptible to the disease because their Eustachian tubes are shorter than those of adults. The inflammation occurs most frequently between the ages of 6 and 18 months. The main symptoms are pulsating pain and a feeling of pressure in the ear. Other symptoms such as decreased hearing, fever and headache are also common.
A sudden and persistent hissing, whistling, ringing, buzzing or humming in the ear – without an external cause of sound – is called tinnitus. It can be triggered, for example, by a sudden hearing loss, various illnesses, stress or certain medications. If no cause can be identified, doctors speak of idiopathic tinnitus.
For a wide variety of congenital or acquired reasons, hearing function can be impaired on one or both sides. Doctors distinguish between different forms of hearing loss, conductive hearing loss and sensorineural hearing loss. In older age, almost everyone also develops presbycusis. Hearing loss can vary in severity. In some people, hearing is only slightly impaired, while others are completely deaf. Children born with hearing loss or deafness often have problems learning to speak.
In otosclerosis, the otherwise mobile ossicles stiffen. The cause of this is not yet clear. The consequence of otosclerosis is hearing loss.
The eardrum can be ruptured by direct or indirect force, for example by the improper use of cotton swabs when cleaning the ear canal or by rapid changes in air pressure (explosion, etc.). Such an eardrum injury (eardrum rupture) manifests itself in stabbing pain and sudden hearing loss. Sometimes blood also leaks from the ear canal, and the affected person complains of dizziness. In most cases, a ruptured eardrum heals on its own and without consequences.
