"What was that? Could you speak up deary! My hearing isn't What it used to be!"
Everybody knows that the easiest way to solve a hearing problem is with a hearing aid. There are two main types of hearing aids, as there are two types of deafness.
For People with Sensor neural hearing loss, (loss of hearing from just hearing too many loud sounds) can use a standard analogue hearing aid or a digital hearing aid. Then on the other hand there is conventional hearing loss (loss of hearing due to infection est.). These people must use a hearing aid known as a Bone Conduction hearing aid, which works differently form an analogue or a digital hearing aid.
If you do not already understand the basic concepts of the two explained types of hearing losses, please read the "Deaf Scientifics" page. That page will explain hearing loss and how the ear works.
Now, the first hearing aid that I will explain is the analogue hearing aid. You can describe a hearing aid to be similar to a karaoke system, because they both have similar parts. The first part of both the hearing aid and a karaoke system is the microphone. The microphone picks up all of the sound directed at the hearing aid, and then sends it through a wire to the next stop.
The next part of the hearing aid is the amplifier. The amplifier is what makes the sound louder, in the karaoke system this would be on the box with the volume control. Because Sensor neural hearing loss will normally decrease the sensitivity of your ear to sound by a large degree, the amplifier becomes the sole purpose for the hearing aid. What the amplifier dose is increases the voltage of the signal coming from the microphone using the battery. If you know about circuitry and sound systems, you should know how increasing the voltage of a sound signal would increase the volume of the final sound that comes out of the speaker.
Now the sound signal arrives at its final destination. As you might of already guessed that destination is the speaker. The speaker is normally attached to the rest of the hearing aid by a tube that is fit into a custom earpiece, which is inserted into the ear hole. Today you can find analogue hearing aids that have many other mechanisms in them too. An example of this is the telecoil, which is a system that is used in many public places. It is just like a wireless microphone, just that every one with a hearing aid has their own receiver.
The next hearing aid is the digital hearing aid. This works virtually exactly the same as the analogue hearing aid except for one thing. After the microphone has received the sound it is sent to a small computer on the hearing aid, which turns into a digital signal. The computer then automatically edits then sound to get rid of any unwanted sound (like wind, muffled talking and interference). The computer then returns it to an analogue signal and sends it to an amplifier. After that point it works the same as an analogue hearing aid.
The final variation or hearing aid is the Bone Conduction Hearing Aid (BCHA). This is for people who have no hearing from their ears what so ever. To clearly understand how this works, I would like you to conduct this simple experiment.
First plug your ears and then say something. You should be able to hear yourself. Though your voice was a little muffled you could still understand what you said to an extent. This is what the BCHA is based on. Even if you have no hearing, the sound you make will still vibrate in your skull.
So what the BCHA does is picks up the sound with a microphone and than turns it into vibrations directed on your skull. These hearing aids are normally fit onto a pair of glasses or on a headband. Though the sound quality is not nearly as good as normal hearing, it is still better then nothing.
Now that you know how a hearing aid works, this is a list of some of the many ways that hearing aids are made and used.
Behind the Ear (BTE) These aids are the more commonly used then any other kind. The entire device is held behind the ear with a small tube coming out around the top that is inserted into the ear with a custom mold. The actual sound may pass through this tube or it might contain a wire, and the speaker is inside the fitted earpiece.
In the Ear (ITE)
Body Worn Hearing Aids
Now, even with Hearing aids there are still some things that restrict deaf people. The following things are a few examples of things that still restrict deaf people, and their solutions.
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