Hearing loss has been called the invisible handicap yet the impact on quality of life can be profound.
Most hearing loss happens so gradually that you may not notice it until it becomes a big problem. The people around you will notice first.
The human ear is a remarkably complex sound analysing system, capable of detecting sounds over an incredibly wide range of intensity and frequency.
A person with normal hearing can hear everything from the faintest whisper of the breeze to the roaring of a jet engine. Normal hearing alerts us to dangers – for example our ears can give us information about the location and speed of an approaching vehicle. With good hearing we are able to listen selectively, focusing on one conversation without missing a word. We are able to appreciate the beauty of a string quartet and the sound of loved one’s voice.
When hearing is lost, the sounds of life begin to fade. For most people this is a gradual process. Typically the sounds in the higher frequencies begin to disappear first – birds chirping in the trees become fainter and fainter – music becomes less clear. Since the lower frequencies are usually heard better or even normally, it isn’t unusual for people to think that there is no problem as it is easy to forget what things sounded like, especially since many of the softer sounds are things we often tend to tune out anyway.
As the hearing loss worsens, the sounds necessary for understanding speech begin to be affected. Soft high frequency consonants are no longer heard and it becomes difficult to reliably distinguish one sound from another. You may not always be able to understand what is said, especially when there is background noise. You need to turn the TV volume louder than before. It seems like people mumble sometimes but other times you understand perfectly. It is natural to think that people are not speaking clearly, when in fact it is your hearing that is not clear. Because your problem cannot be seen, your hearing loss is not understood and you may appear to be unsociable. The comment “He can hear perfectly when he wants to” is a common complaint from family and friends of the hearing impaired.
What causes hearing loss?
As the ear is quite complicated, a problem with any part of the system can cause a loss of hearing. The medical profession defines two main categories of hearing loss:
Conductive hearing loss is caused by any problem in the outer or middle ear that interfere with the transmission of sound. This interference can be caused by such things as a large build-up of earwax, infections or growths in the outer ear, holes in the eardrum, a disease called otosclerosis (which causes the ossicles to become fixed and unable to vibrate) or genetic factors.
Conductive hearing loss can often be corrected or improved with medical intervention but when that is not possible, hearing instruments can usually help.
Sensorineural hearing loss is the term used to describe problems in the inner ear, either in the cochlea, hearing nerve or auditory pathway (often called nerve deafness). This type of hearing loss can be caused by many things but the most common cause is deterioration of the hair cells in the cochlea due to aging and/or exposure to loud sounds. 90% of all hearing losses are the sensorineural type. This kind of problem can rarely be helped medically but fortunately instruments can help.
A third type of hearing loss is called mixed hearing loss and is simply a combination of conductive and sensorineural problems. Many people with mixed hearing loss are also able to benefit from hearing instruments.
The sooner you become aware that you may have a hearing loss, the sooner you can have a thorough hearing evaluation and begin to benefit from the appropriate treatment.