Hearing Loss – The Invisible Handicap

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It is estimated as many as 3.5 million Canadians suffer from hearing loss. That’s a staggering number especially if you consider that a large percentage of hearing loss goes undiagnosed. It is one of the world’s most common, but often ignored problems. With an aging population, and an increasing amount of noise in the daily environment, the number of people with hearing loss is rising

Hearing loss has been called the invisible handicap. Unless you engaged a hearing impaired person in conversation you would never notice they had a disability. It is important to note that most hearing loss is not like listening with the volume down. Instead you would start to find certain sounds more difficult to hear than others. High pitch sounds tend to go first, so you start to lose the ability to hear the high frequency consonants in speech (the “F” “TH” and “S” sounds are prime examples). As a result, words start to sound less clear and critical speech information is lost. So even though conversation can be heard, it takes a greater and greater effort to do so. One of the most overlooked consequences of hearing impairment is mental fatigue and frustration. This eventually can lead to withdrawal from otherwise healthy social interaction, which further compounds the problem. So while the cause of hearing loss is physiological, the detrimental effects are largely psychological.

So how do you know if you have a hearing loss? Probably, the people around you will notice it first. For most people hearing loss is gradual. As hearing worsens the brain adapts to the new input levels and, to the hearing impaired person, the world sounds “normal”. In reality, the brain is receiving less and less auditory information. Early signs of hearing loss can be turning up the TV, difficulty hearing in crowds or complaining that people are mumbling. Unless there is sudden onset or unilateral loss (in one ear), the gradual nature of most hearing loss makes it easy to ignore until its having a major impact on your life.

So what causes people to lose their hearing? The ear is a complex system. We can describe the ear in three main parts: the outer ear, the middle ear and the inner ear. The outer ear (the part we can see) acts as a collector and channels sound towards the eardrum. The middle ear system, which includes the eardrum and ossicular chain (the middle ear bones) acts as an amplifier, and sends the sound vibrations to the inner ear. The inner ear, or cochlea, is the actual hearing organ. Inside the cochlea are thousands of hair-like cells that are connected to fibers of the hearing nerve. These fibres send messages to the brain for processing and interpretation. A problem with any part of this system can cause a loss of hearing.