How does hearing Work?
The outer ear collects sound waves and works like a funnel to send them through the ear canal that leads inside the ear. At the end of the ear canal is the eardrum (tympanic membrane). The tympanic membrane is a thin membrane that vibrates when sound waves strike it. It divides the area called the outer ear from the middle ear. It is attached to a set of three tiny bones in the middle ear. These bones are called the hammer (malleus), anvil (incus), and the stirrup (stapes). The bones pass the vibrations of sound waves to a small organ in the hearing part of the inner ear called the cochlea, which is a coiled structure like a snail shell. The inner ear is filled with a thin fluid that transmits pressure changes throughout the cochlea. Inside the cochlea are tiny hair cells that pick up sound vibrations from the fluid and cause nerve impulses in the auditory nerve. The auditory nerve carries the message to the brain, where it is interpreted as sound
* Canadian Academy of Audiology
do I have a hearing loss?
Do you think you have a hearing loss? Often it is difficult to tell because hearing loss usually occurs gradually such that the person is not aware of it. Use the following indicators to see if you MAY have a hearing loss:
- Do family members complain about your inability to hear?
- Do you have difficulty understanding what people are saying in noisy places?
- Do you often ask people to repeat themselves?
- Do you find yourself avoiding social situations because you cannot hear?
- Do you turn up the volume on the TV so loud that others are complaining?
- Do you have difficulty determining which direction sounds are coming from?
- Do you have a history of exposure to loud noise (loud concerts, guns, construction, etc.)?
- Do you have difficulty hearing familiar sounds like the telephone and/or doorbell?
If you experience any or all of these problems on a consistent basis, you may have a hearing loss. You are not alone. 10% of the Canadian population suffer from some level of hearing loss; as many as half of these people are under the age of 65. You may not notice hearing loss in yourself, but others around you will.
what is tinnitus?
Tinnitus is the term used for noises or sounds which are heard in one or both ears or in the head which do not come from an external source. They are often described as a high-pitched ringing but can also be described as a buzzing, hissing, pulsing, whistling, roaring, or various other sounds. Tinnitus can be very mild in loudness and only noticeable in a quiet room or it can become extremely loud and annoying to the point where the sufferer hears nothing else. It can be present all of the time or occur intermittently.
The loudness of the tinnitus often varies in intensity depending on several factors including stress, diet, and noise exposure. Tinnitus, like chronic pain, is subjective. Two people may report similar characteristics yet be affected in a significantly different manner. The severity of the tinnitus is largely a function of the individual reaction to, or perception of, the tinnitus. Many tinnitus sufferers have difficulty sleeping and/or concentrating, and many are depressed.
As many as 360,000 Canadians suffer from annoying tinnitus. 150,000 Canadians experience a degree of tinnitus that significantly affects their quality of life*. While tinnitus does not cause hearing loss, it may accompany decreased hearing and other symptoms such as a feeling of pressure in the ear and/or unsteadiness, dizziness or vertigo. However, for many people with tinnitus it occurs alone with no other symptoms.
*Tinnitus Association of Canada
what are the causes of tinnitus?
The exact mechanism underlying tinnitus, what it is and where it is, is unknown at this time but research continues around the world. Some of the causes of tinnitus are:
- Disorders in the outer ear such as excessive ear wax (cerumen), a foreign body, perforated eardrum, or a hair touching the eardrum. Often, removal of the problem (wax, hair, etc.) will relieve the tinnitus.
- Disorders in the middle ear such as an ear infection, otosclerosis, or a benign tumor.
- Disorders in the inner ear such as damage due to noise exposure, presbycusis (hearing loss from aging), Meniere’s Disesase which is also accompanied by episodic dizziness, nausea, ear pressure, and fluctuating hearing loss. Noise exposure is the leading cause of tinnitus and is very preventable with the use of hearing protection.
- Trauma to the head or neck, such as concussion or whiplash, can cause long-lasting tinnitus.
- Certain medications can cause head noises. They include anti-inflammatories such as aspirin and quinine, some sedatives and antidepressants, and certain antibiotics and chemotherapeutic agents including furosemide, cisplatinum, streptomycin, neomycin, and kanamycin.
- One of the most difficult causes of tinnitus to diagnose is a vestibular schwannoma (acoustic neuroma) which is a small tumor pressing on the vestibular nerve leading from the cochlea to the brain. Tinnitus may be the only initial symptom.
- Various other causes such as high or low blood pressure, diabetes, vascular disorders, temporomandibular (jaw-joint) disorders, allergies, syphilis and thyroid dysfunction.
Although the majority of people with tinnitus have an associated hearing loss, the presence of tinnitus does not mean that one has decreased hearing.
*Tinnitus Association of Canada