Identify Hearing Loss

Causes of Hearing Loss

Hearing loss has a wide range of causes;

• Age related - a natural decline in hearing as we get older and the most common cause of hearing loss.
• Sound related trauma to the ear impacting the hair cells. Exposure to noise (hunting, construction/plant noise, engine) can cause permanent hearing loss.
• Wax build-up can stop sound from reaching into the ear canal.
• A viral infection that has affected the inner ear or auditory nerve. (This can be caused by mumps, measles or rubella)
• Perforation of the eardrum caused by changes in air pressure commonly experienced with flying and scuba diving. Too much pressure on a cotton swab or pressure from a middle ear infection can also cause a perforated eardrum.
• A disease called Meniere's, causing abnormal pressure to the inner ear.
• A non-cancerous tumour of the auditory nerve called acoustic neuroma.
• Drug interactions that affect the hair cells can be caused by drugs such as large doses of aspirin, quinine, aminoglycosides, diuretics and certain antibiotics.
• Other conditions such as multiple sclerosis, meningitis, benign growths, a brain tumour, or stroke.

Levels of Hearing Loss

Profound Hearing Loss: The most extreme level where you can only hear very loud speech, or none at all. You often rely on visual clues, hand gestures, and lip reading.

Severe Hearing Loss: To have effective understanding you must be in close range or face-to-face contact with the speaker and they must be loud. In some cases you may still miss up to 100 percent of what's presented.

Moderate Hearing Loss: You can miss 50-75% of speech. Face-to-face is often good while short distances can be a problem and visual clues are important. You still have a problem with normal conversations and hearing consonants in words.

Mild Hearing Loss: You are only missing 25 to 40% of a speech signal. Hearing signals in the background is difficult and those you are having a direct discussion is fine unless there's a lot of background noise or they have a weak voice. Your brain is receiving more signals and trying to piece together what's being said.

Unilateral Hearing Loss: Defined as hearing loss in one ear. Depending on the level of loss the typical symptom is having difficulty locating where the sound is coming from. You can also have difficulty hearing distant sounds if your 'good ear' is being directed to the person you are talking to.

In addition to 'Levels' of hearing, lost hearing is also measured against the range of speech frequencies or 'Pitch'. Sounds that we hear every day range from the high pitch of a birds chirp to the low pitch of a tube. The high pitch is referred to as treble, while the low pitch sounds are called base. A loss in hearing will not affect all of the frequencies and pitches in the same way.

Types of Hearing Loss

Sensorineural: Also called "cochlear", "inner ear", "nerve loss", or "nerve deafness" is the most common type of hearing loss, considered irreversible and accounts for 90% of hearing impairments. The inner ear or cochlear nerve itself has been damaged in some way and it can progress to total deafness. It is often seen with age related changes, genetics, noise exposure, inner fluid disturbances and changes in inner ear blood circulation. This type of hearing loss is not usually treatable through medicine or surgery. Hearing aids are often the most beneficial solution.

Conductive: This type of hearing loss is where sound is blocked from the outer to inner ear. It may be caused by earwax build-up, fluid in the middle ear ('glue ear' in children), a middle ear infection (Otitis media), or a perforation or hole in the eardrum. It may also be due to a disease of any of the three middle ear bones. You can often sense that your ears are plugged, crunchy foods sound loud to a person with conductive hearing loss, and you may have to stop chewing to hear a conversation. These symptoms can occur when the eustachian tube, that opens to the throat is plugged. An inflammation of the tube may keep it closed causing a build-up of fluid in the middle ear. The remedy for conductive loss can often be easier than sensorineural with either medical or surgical correction. If this is not an option a hearing aid can be the answer.

TIP: one way to demonstrate conductive loss is to carefully and safely put your fingers over your ears. You will feel that your ears are plugged and you are mildly hearing impaired. This demonstration typically gives you a 25-decibel hearing loss or a 'very mild' hearing loss.

Temporary: Temporary hearing loss can be caused by earwax buildup, an ear infection, but most commonly due to loud noises. Over 30 Million Americans are exposed to loud noises daily. This noise can cause damage to the inner ear called Noise-Induced Hearing Loss (NIHL). It may be accompanied by tinnitus or 'ringing of the ears' which fortunately can diminish and be gone over time. Alternatively, if you are constantly exposed to this level of noise the condition can become permanent. You are in a dangerous situation if you are regularly exposed to situations where you are 3 feet away from someone and cannot hear due to a high noise level. These situations can be corrected by avoidance and the use of earplugs or other protective devices. With conditions like tinnitus that may persist, its important to consult a physician to make sure the cause is not related to a medical condition including high blood pressure or medications, or dietary related such as excessive caffeine which may be contributing to the problem.

Temporary hearing loss due to ear infections is also called Otitis Media. This is a very common form of hearing loss that affects 70% of all infants and young children.

At advanced ages a high frequency hearing loss occurs that has been given the name Presbycusis.

Mixed Hearing Loss: This is simple a combination of both conductive and sensorineural hearing loss. In many cases the conductive part may be treatable while the sensorineural part is often permanent.

Preventing Hearing Loss

There are a number of simple measures you can take to reduce your risk of hearing loss:

• Be cautious of three things about noise: 1. How Loud, 2. How Long, and 3. How Close.
• Avoid loud noises, limit your exposure and/or be prepared to wear ear protection such as earplugs or ear protection devices. Earmuffs or simply holding your hands over your ears will help.
• Wear earplugs or muffs when using loud equipment, especially for a prolonged time (i.e. lawn mowers, power saw, leaf blower).
• Lower the volume on car stereos, portable radios, and iPods. If you are standing next to a person wearing earphones and you can hear the words and lyrics - it's causing damage! Headphones that cover the ear are preferable to ear-bud style headphones.
• In the workplace, be aware of the noise levels and workplace regulations. At 90 dB or higher it can be regulated that employees must wear earplugs.
• Education is the first line of defence. Children should be taught at a young age about the dangers of loud music and other noises.
• Get immunized for certain diseases that can cause hearing loss such as measles and H-flu meningitis.
• Ask your Doctor about high blood pressure and Meniere's disease, two conditions that can lead to hearing loss.
• Avoid prolonged and heavy use of medications unless prescribed by your Doctor.
• Don't put cotton tipped swabs or fingers in your ears and never blow your nose too hard.
• Have your hearing screened regularly, especially if you have a hobby or job that has a high sound risk.
• Don't hesitate to see your Doctor if you experience any sound loss in one or both ears.