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## Input devices ### Magnetic strip codes A magnetic strip is a short length of magnetic-coated plastic tape printed on the surface of or sealed into a ticket or card. It contains information to identify the ticket or card and its user. The card is read by swiping it which involves moving the magne...

## Input devices ### Magnetic strip codes A magnetic strip is a short length of magnetic-coated plastic tape printed on the surface of or sealed into a ticket or card. It contains information to identify the ticket or card and its user. The card is read by swiping it which involves moving the magnetic strip through a reader so that the strip can be read. These strips are used on bank cards to identify the card holder's bank account, so that the card holder can perform banking transactions. Cards with encoded magnetic strips can quickly identify and allow access to card holders entering buildings. These cards can also be used for security purposes. Examples of other uses include phone cards and debit cards for cell phones. The magnetic strip on these cards contains information about the amount of money left on the card. ### Audio and video input devices The different types of audio and video input devices include the following: * Voice data entry or voice recognition systems * Sound capture devices * MIDI instruments * Biometric systems * Digital cameras * Smart cards * Digital video cameras * Motion-sensing devices. ### Voice data entry or voice recognition systems Voice recognition systems require the use of a microphone. This system accepts the spoken word as input data or commands. Human speech is complex, because it carries tones, inflections and emphasis of various parts of words and phrases. The computer is programmed to recognise certain patterns of speech. Using a microphone, human speech is coded into a sequence of electronic signals. These signals are compared to a set of stored patterns. If they match, the command or data being entered is accepted by the computer and processed. Simple commands can be used to control machines or even 'type' letters in a word processor. Voice recognition has become important in many areas of our lives. It has made life easier for people with movement difficulties, such as those who are paralysed, and who, with suitable equipment, can now operate a wheelchair, lighting... using voice...