They’ve been around since the turn of the 20th century and have made the difference between being cut off from the world of sound and living a normal life. The hearing aid, which basically amplifies sound waves, has since evolved to become a sophisticated, subtle and relatively inexpensive device.
Meant for people with severe hearing loss, a hearing aid is available in a wide variety of options. But not all individuals with hearing loss are candidates for a hearing aid and you must be tested by an audiologist and / ENT specialist to determine whether you need one.
A hearing aid is an electronic device worn either in the ear (canal) or behind the ear. It has three components – a microphone, which collects external sounds and converts them into electrical signals; an amplifier, which amplifies the sound signals or makes them louder; and a speaker, which directs these amplified sound signals through the ear.
Individuals who benefit from hearing aids are those whose hearing loss is due to damage to the small sensory hair cells in the inner ear or cochlea. It is these cells that convert sound signals to nerve impulses, which are then relayed to the brain. When the hair cells are damaged, the hearing loss that results is called ‘sensori-neural hearing loss’, which may take place due to many factors such as disease, ageing or injury from certain medication.
The hearing aid basically amplifies sound vibrations which enter the ear, or make them louder so that they can be picked up by the undamaged hair cells. However, there is a limit to how much these sound signals can be amplified. If the hair cells are extensively damaged, further amplification does not work.
If you have severe hearing loss and think you need a hearing aid, visit an ENT (ear, nose, throat) specialist, who is also called an otolaryngologist or visit an audiologist. An audiologist will perform various tests and determine the type and severity of hearing loss. With the audiologist’s reports, an ENT specialist will be able to determine whether you are an appropriate candidate for this device.
Hearing aides are basically of two types – analog and digital.
Analog hearing aids convert sound waves into electrical signals, which are amplified. Audiologists programme and adjust the device according to the specifications of the patient. They are thus customised to meet your needs. They may also be programmed to suit different environments such as a quiet one like an office or an outdoor, noisy environment.
Digital hearing aids convert sound waves into numerical codes before amplifying them. These hearing aids can be programmed more easily and precisely.
Hearing aids are also classified on the basis of where and how they are worn.
Open-Ear hearing aids are the most modern type of device. It is subtle and barely visible and eliminates the echo that affects other types of devices.
Behind-the-Ear (BTE) devices are worn behind the ear. Magnified sound waves are funneled through a tube that transfers them to an ear mould which fits in your ear.
In-the-Ear (ITE) hearing aids are custom-built and fit inside the ear.
In-the-Canal (ITC) devices are smaller than ITE hearing aids. These are also custom-built so that they take the shape of the ear canal.
Completely-in-the-Canal (CIC) hearing aids are so tiny that they fit inside the ear canal and are barely noticeable.
The efficacy of the device depends on the type and severity of your hearing loss. After the audiologist assesses the nuances of your condition, he / she will advise you on the type of hearing aid that best suits you.
Also, if you suffer from hearing loss in both ears, it is advisable to use a hearing aid for each ear. This helps the brain to process sound signals most naturally rather than by receiving amplified sound from only one ear. Remember, a hearing aid does not restore hearing; it magnifies sound waves to assist hearing and minimise hearing loss. Also, though hearing aides can help to a great extent, your sense of hearing may never be what it once was.