The ear is composed of 3 parts: the outer, the middle, and the inner ear. The outer ear consists of the pinna and the ear canal. From the pinna, sound enters the ear canal increasing the loudness of certain pitches that are important for understanding speech.
Separating the outer ear from the middle ear is the eardrum, and connecting the eardrum to the inner ear are the ossicles: 3 tiny bones best known as the hammer, the anvil and the stirrup (malleus, incus and stapes). The ossicles serve to pass the vibrations from the eardrum to the oval window at the cochlea, while at the same time amplifying and intensifying the movement. The middle ear also has a connection to the nose and throat via the Eustachian tube. This is the tube responsible for equalizing pressure when atmospheric changes occur; for example, on airplanes or while diving under water.
When sound cannot be transmitted normally through the ear canal and/or middle ear to the cochlea, it is referred to as a conductive hearing loss. Wax build-up, holes in the eardrums or ear infections are typical causes of conductive hearing losses.
As sound vibrations are transmitted to the cochlea in the inner ear, they set tiny hair cells in motion. These hair cells transform the vibrations into nerve impulses, which are picked up by the acoustic nerve and sent to the brain.
The inner ear is very fragile, and many things can go wrong. Exposure to loud sounds can damage the hair cells, reducing the number of available hair cells that can convert sound vibrations into nerve impulses transmitted to the brain. Disease, viruses, some medications and infections can also injure the inner ear, in addition to the normal aging process. Hair cells may deteriorate as well as nerve pathways, preventing the signal from the ear from reaching the brain. These types of problems are referred to as sensorineural hearing losses.
Sensorineural hearing losses affect our sensitivity to sounds, as well as our ability to understand words. For example, individual words may seem unintelligible during discussions, making it difficult to follow in conversations.
Hearing losses that are caused by both conductive and sensorineural impairments are termed mixed hearing losses.
No matter what the nature of your hearing loss, a hearing care professional can conduct a painless investigation which takes less than an hour to perform, to evaluate your hearing loss and recommend the best treatment.