The ear is comprised of three main sections, including the outer ear, middle ear and inner ear.
The Outer Ear
The outer ear consists of the pinna (the portion that can be seen), the ear canal, and the tympanic membrane (eardrum). The pinna is comprised mostly of cartilage and functions to funnel sounds down into the ear. The ear canal is approximately 2.5 cm in length, 5-7 mm in diameter, and consists of ceruminous glands in the outer 1/3. These cerumenous glands function to produce cerumen or ear wax. The tympanic membrane is transparent and cone shaped in appearance, is 55 to 90 mm2, and stretches across the entrance to the middle ear.
The Middle Ear
The middle ear is a 2 cm3 air filled cavity lined with a mucous membrane, houses 3 middle ear bones: the malleus (hammer), the incus (anvil), and the stapes (stirrup), and connects to the upper part of the throat via the Eustacian tube. The middle ear bones are the smallest bones in your body. Simplistically, the middle ear functions to transmit and amplify the sound waves from the air filled outer ear to the fluid filled inner ear, the organ of hearing.
The Inner Ear
The inner ear has two primary functions: balance and hearing. The semicircular canals and the vestibule are responsible for the balance system while the cochlea is responsible for the hearing system. The cochlea is a fluid filled snail shaped organ that is 2 ¾ turns and 35 mm in length, contains thousands of tiny hair cells. These hair cells are displaced by the incoming sound waves and function to convert the sound waves from the outer and middle ear into electrical impulses for interpretation by the brain via a number of chemical reactions.
Types of hearing loss:
Conductive Hearing Loss
This condition is often the result of an obstruction or blockage of the outer or middle ear. Common causes include cerumen buildup, infection or fluid in the middle ear, or abnormal bony growth around the middle ear bones. In some cases, a conductive hearing loss can be treated with medical intervention.
Sensorineural Hearing Loss
This condition is often the result of damage to the inner ear or the central auditory system. A sensorineural hearing loss can be genetic or acquired, but more commonly is the result of damage to the hair cells of the inner ear due to presbycusis or aging.
Mixed Hearing Loss
This condition is a combination of both a conductive hearing loss and a sensorineural hearing loss.
Degree of Hearing Loss
The degree of hearing loss varies from person to person and there are several degrees of hearing loss, including mild, moderate, severe, and profound. When someone has a mild hearing loss, he/she typically presents with difficulties hearing in background noise. Someone with a moderate hearing loss, on the other hand, presents with some difficulties hearing soft sounds and hearing in background noise. A person with a severe hearing loss presents with difficulties hearing all sounds with the exception of very loud sounds. And finally, someone with a profound hearing loss is only able to hear extremely loud sounds.
Warning Signs of Hearing Loss
The most common warning signs of hearing loss include:
- speaking louder than necessary in a conversation;
- constantly asking for words to be repeated;
- straining to hear;
- misunderstanding conversations;
- favouring one ear;
- thinking that people always mumble;
- turning the television or radio up louder than usual;
- having difficulty hearing on the telephone;
- withdrawing from social contact;
- ringing or buzzing in the ears (tinnitus);
- appearing dull and disinterested; and
- being slow to respond.
Adapted from the CASLPA website.
Cerumen (Earwax): What is it and how do I Manage it?
The production of earwax is normal and an important biological occurrence. Earwax is a brown-yellowish sticky substance that functions to protect the tissues of the ear canal and the tympanic membrane from dirt and foreign particles. The amount of earwax production is variable and can increase as you age. When a significant amount of ear wax has accumulated in the ear canal leading to an obstruction, cerumen management is typically employed.
Cerumen management is performed in an effort to remove the earwax and debris obstructing the ear canal. The most common method of cerumen management is the use of such instruments as curettes, wax spoons, and forceps, but some clinicians use irrigation or suction. At home, the use of a couple of drops of room temperature oil into the ear canal to aid in the moistening of earwax can be employed. The insertion of any tool into the ear canal, such as Q-tips, is not recommended.