These are particularly useful for improving hearing of people affected with SNHL. It is an electronic device that receives sound through a microphone, sends it though an amplifier. The amplifier increases the strength of the signals and sends them to the ear, through a speaker attached to the system. Hearing aids may be used behind the ear, in the ear or in the ear canal or completely inside the ear canal. There are two types of electronic hearing aids available - analog and digital.
Analog aids are adjustable and are custom made to meet the needs of each user. It can be programmed for different listening environments. They are less expensive. Digital aids convert sound into numerical codes before amplifying them. Digital circuitry can be used in all types of hearing aids.
A cochlear implant is a small complex electronic device that helps a person who is profoundly deaf. The implant consists of two portions – external and internal. The external portion is placed behind the ear and the second portion is surgically placed under the skin. The implant consists of a microphone, a speech processor and a transmitter & receiver and a collection of electrodes. The cochlear implant cannot restore normal hearing. Rather it helps a deaf person by giving useful representation of sounds in the environment and understands speech. They differ from hearing aids in the way they work. Cochlear implants bypass damaged portions of the ear and simulate the auditory nerve. Signals from the implant are carried to the brain through the auditory nerve that recognizes the signals as sound. Thus hearing through a cochlear implant is much different from normal hearing and requires time to learn and relearn. However, it definitely helps the deaf by making them understand warning signals and sound from the environment and helps them in conversation by telephone.