Hearing aids make sound (all sounds louder); they don’t restore normal hearing nor are they quite as efficient as glasses are for the individual who needs them. Hearing aids come in a variety of sizes. The audiologist will help determine which hearing aids would be the most beneficial for individual hearing losses.
Parts of a Hearing Aid
• a microphone, to pick up sound
• an amplifier, to make the sound louder
• a speaker, to deliver the sound into the ear
• batteries, to power the hearing aid
• earmold, sound is directed through the outer to middle ear by way of ear hook and earmold
There are 3 major hearing aid types:
• Analog Adjustable: amplify both speech and other sounds in equal volume. They are the least expensive and although it is possible to control the loudness to some degree, there is little flexibility in adapting these hearing specifically to a very complicated hearing loss.
• Analog Programmable: contain a computer chip that allow the hearing aid to be more successfully programmed to individual hearing losses. They can be programmed to adapted to several different environments: individual conversations, table conversation in a restaurant, telephone conversations, larger group meetings. A remote control can be used to change the programmes.
• Digital Programmable: are the most advanced of hearing aids. They can analyze the environment and make adjustments to the sound. They allow a greater flexibility in programming than do analog hearing aids. They are also the most expensive. Digital hearing aids do tend however provide a cleaner and clearer sound, especially which the presence of background noise. However some Deaf and hard of hearing individuals continue to prefer their analog over the digital hearing aids. It largely depends on the type of hearing loss and individual preferences. Other people wear one analog in one ear and one digital in the other.
Technology has progressed to such an extent that the large body hearing aids that once were worn are now a thing of the past. There are essentially 3 styles of hearing aids available: behind the ear, in the ear, and in the canal. Below are a couple of diagrams of the parts of the ear, followed by the different styles of hearing aids.
• Behind-the-ear (BTE): are used for all types of losses, but especially the severe and profound hearing loss. All the parts of the hearing aid are housed in the case which fits behind the ear. A connecting tube channels the sound into the earmold and into the middle ear.
• In-the-Ear (ITE): are generally used by those with mild to severe hearing losses. The parts of this hearing are found in the case that sits at the entrance of the ear canal. They are small which can make them more difficult to manage and because they would need to be changed regularly as a child grew, children rarely wear them.
• In-the-Canal (ITC): can be used by individuals with mild to moderate hearing losses. The parts are housed in the case which fits entirely in the ear canal. They are fitted to the shape and size of each ear canal. They also are not recommended for children because of the expense needed to continually change them as the child grew.
CROS Hearing Aids (Contralateral Routing of signals): When one ear has a profound hearing loss and will not benefit from the usual hearing aid, a CROS hearing aid can be worn and linked with either the behind-the-ear or in-the-ear hearing aids so that the sound signal from the one side can be transferred to the opposite hearing aid/ear. The BTE or ITE hearing aid will then receive the sound signal from both sides of the head. This gives the child/student/individual greater access to “surround” sound which in classrooms during discussions or in large meetings where many different people will be taking turns talking, can be a great benefit. Localizing from where the sound originates, is a major problem for individuals with a hearing loss. By the time they figure out from which direction the sound is coming from, they have missed much of what has been said, and then the speaker changes.