The basics of a hearing instrument

The hearing aid is a transducer. It’s an instrument which pickup the sound wave from the environment and the convert to an electrical signal with the necessary amplification as per the individual hearing loss and reconverts into acoustic signal which is directed down to the canal of the ear.

In the front stage of the hearing head the microphone pickups the sound and the end near the ear canal the loud speaker (Receiver) delivers the acoustic sound. In between the necessary amplification is carried out by electronic circuits.

Based on the technology involved in the electronics circuit its divided into Analog and Digital Hearing aids
Analogue hearing aids:
Analogue hearing aids amplify sound signals picked up by a microphone and convert them into small electrical signals. These signals are transmitted into the ear in real time. They can be altered according to the needs of the individual user within the limits of the analogue technology.

Digital hearing aids:
Today, many modern hearing aids use digital technology. These are quite different from analogue hearing aids. They transform the sound, convert it into bits, and manipulate it before amplifying the signal. This type of technology is similar to that used in a CD player. A digital hearing aid can be programmed. This means that digital hearing aids can be individually adjusted to suit the specific user by means of a small computer.

The modern digital hearing aid can provide a hearing-impaired person with an improved and more pleasant sound picture.  It can bring back almost near to the normal hearing. A digital hearing aid with advanced directional microphones will greatly help people who suffer from hearing loss, particularly in noisy surroundings.
There are several types of hearing aids. Your best choice depends on the condition of your ear and type of hearing loss.
The most popular types of hearing aids can be divided into four categories:

Completely-in-the-canal (CIC)
The smallest hearing aid is almost invisible in the ear. These hearing aids are suitable only for people with ear canals large enough to accommodate the whole hearing aid. Often used in cases of mild to moderate hearing losses.

In-the-canal (ITC)
This hearing aid is a bit larger than the Completely-in-the-Canal type. The hearing aid is normally used in cases of mild to moderate hearing loss.

In-the-Ear (ITE)

In-the-Ear hearing aids are larger, and may offer more features. They also accommodate larger receivers. This type of hearing aid is easier to handle than CICs and ITCs. Treats a wide variety of hearing impairments.

Behind-the-Ear (BTE)
 The electronics are housed in a case that is fitted behind the ear. Because of a robust design, this type is especially recommended for children. These hearing aids are suitable for treatment of a wide range of hearing losses, including severe hearing loss. Even though placed outside the ear, this design is extremely discreet.

In the most modern BTEs the receiver is placed in the ear canal instead of behind the ear. This makes it possible to downsize the hearing aid and to reduce feedback (whistling) problems.

Cochlear implant

A cochlear implant is an electronic device which is surgically implanted in the inner ear of a person who is profoundly or completely deaf. Unlike hearing aids, the implant does not make sounds louder or clearer. Instead, it stimulates the hearing nerve directly. A cochlear implant will give the hearing-impaired person a sensation of hearing. It is important to understand that it only provides a reduced sense of hearing, not a fully restored hearing sense. Therefore, it takes time, practice and patience to learn how to use a cochlear implant.