Ear Anatomy: A Guide to How Your Ear Works
The human ear is an extremely complicated organ that is part of the auditory system. It captures the sensory input for hearing as well as helps govern your sense of balance, which is critical for mobility. The ear does all of this through its three major parts, which are known as the outer, middle, and inner ear. These parts, in turn, are made up of many smaller parts, many of which are both highly sensitive and delicate. Sound first enters through the pinna before traveling through the external auditory canal, both of which are part of the outer ear. In the middle ear, sound vibrates the tympanic membrane, or eardrum, as well as three tiny bones collectively called the ossicles. The movement of these bones further helps to conduct sound into the inner ear. The eustachian tube is also located there and maintains proper pressure on either side of the tympanic membrane. From there, sound travels into the inner ear, where the cochlea converts it into signals that it transmits to the brain via the vestibulocochlear nerve. This nerve also interacts with the semicircular canals, and together, they manage a person’s sense of balance and orientation.
The sensitivity of the ears means that they can easily be affected by certain conditions and that they can also contribute to others. Meniere’s disease, certain types of migraines, and an inflammation of the vestibulocochlear nerve called vestibular neuritis, for example, can create problems with the inner ear that result in dizziness. In addition to vertigo, Meniere’s disease can also cause hearing loss. This condition may be caused by one or more health-related problems, all of which affect inner ear fluid. These problems include allergies, viral infections, trauma to the head, and an abnormal immune response. Tinnitus, which is a ringing in the ears, is yet another problem of the ear that can be caused by health issues. These issues include earwax blockage, loud noises, or simple age-related hearing loss, include acoustic neuroma, injuries to the head and neck, TMJ, high blood pressure, and atherosclerosis. Benign paroxysmal positional vertigo (BPPV) is a form of vertigo that happens when inflammation or infection disturb the normal movement of calcium stones in the ear. Even minor-seeming things can create problems. For instance, ear wax, which fights infection, can also collect in the ear and result in a blockage, temporarily reducing the quality of one’s hearing.
Modern medicine has come up with a variety of advancements in treatments to reduce the magnitude or even likelihood of hearing loss. One of the most well-known examples is hearing aid technology, which comes in many different forms. An analog hearing aid amplifies sound to transmit into the ear, while a digital hearing aid can selectively amplify certain frequencies for more flexible hearing correction. Hearing aids come in a behind-the-ear style, which fits against the outer ear, and open-fit types that go into the ear canal. The in-the-ear hearing aids go completely inside the ear and are the hardest for others to see. The most advanced devices to aid hearing are implants, which surgeons must install into the skull. There are middle ear implants that are designed to treat sensorineural hearing loss, and there are cochlear implants for more severe cases of hearing loss that transmit sounds directly to the vestibulocochlear nerve.
Hearing loss is not just something that happens to older adults, and it can strike at birth as well. Congenital hearing problems can be hereditary in nature, but they can also be the result of other issues such as low birth weight, German measles, infections transmitted from the mother such as toxoplasmosis or herpes, and tumors.
Parts of the External and Middle Ear
- The Ear
- Ear Anatomy: Gross Anatomy
- A Diagram of the Ear Structure (PDF)
- Definition of Middle Ear
- Hearing and Balance: Middle Ear
Parts of the Inner Ear
- The Inner Ear
- How Does the Ear Work?
- Auditory System
- Hearing: The Structure and Function of the Inner Ear
Health Problems That Affect the Ears
- Meniere’s Disease
- Middle Ear Infections
- Dizziness and Vertigo (PDF)
- Eustachian Tube Dysfunction
Modern Medicine and Hearing Issues
- Hearing Loss in Children: Treatment and Intervention Services
- Treatments for Hearing Loss
- Hearing Loss Treatment
- Treating Hearing Loss
- Hearing Aids and Other Devices for Hearing Loss
Congenital Hearing Loss