1. Cochlear Implant:
A cochlear implant (CI) is a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf or severely hard of hearing. The cochlear implant is often referred to as a bionic ear.
As of April 2009, approximately 188,000 people worldwide had received cochlear implants; in the United States, about 30,000 adults and over 30,000 children are recipients. The vast majority are in developed countries due to the high cost of the device, surgery and post-implantation therapy. A small but growing segment of recipients have bilateral implants (one implant in each cochlea).
http://en.wikipedia.org/wiki/Cochlear_implant
2. ElectroLarynx -
(abbreviated EL or AL for Artificial Larynx) There are several such devices on the market - of basically two types. They are all battery powered, but with one type of unit, you place it against your throat, push a button, and the machine transmits a vibration noise to your throat which you then form into words and sounds with your lips, teeth, and tongue. With the second type, the vibration sound is transmitted directly into your mouth via a small tube - words and sounds are made in a similar manner. Regardless of the type, the "sound" produced sounds something like THIS ("Hello! How are you?" on an electro-larynx).
http://www.webwhispers.org/library/Electrolarynx.asp
3. The Braille
- 200px-DSC_4050-MR-Braille.jpg (11.32 KiB) Viewed 22601 times
system is a method that is widely used by blind people to read and write, and was the first digital form of writing. Braille was devised in 1821 by Louis Braille, a blind Frenchman. Each Braille character, or cell, is made up of six dot positions, arranged in a rectangle containing two columns of three dots each. A dot may be raised at any of the six positions to form sixty-four (26) possible subsets, including the arrangement in which no dots are raised. For reference purposes, a particular permutation may be described by naming the positions where dots are raised, the positions being universally numbered 1 to 3, from top to bottom, on the left, and 4 to 6, from top to bottom, on the right. For example, dots 1-3-4 (⠍) would describe a cell with three dots raised, at the top and bottom in the left column and on top of the right column, i.e., the letter m. The lines of horizontal Braille text are separated by a space, much like visible printed text, so that the dots of one line can be differentiated from the Braille text above and below. Punctuation is represented by its own unique set of characters.
http://en.wikipedia.org/wiki/Braille