• Speech recognition is a is a computer software program or hardware device with the ability to decode the human voice. 
  • Today, this is done on a computer with automatic speech recognition (ASR) software programs.
  • Many ASR programs require the user to train the ASR program to recognize their voice so that it can more accurately convert the speech to text.
  • For example, you could say open Internet and the computer would open the Internet browser.
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How does it works?
  • Voice recognition software on computers requires that analog audio be converted into digital signals, known as analog-to-digital conversion. 
  • For a computer to decipher a signal, it must have a digital database, or vocabulary, of words or syllables, as well as a speedy means for comparing this data to signals.
  • The speech patterns are stored on the hard drive and loaded into memory when the program is run.
  • A comparator checks these stored patterns against the output of the A/D converter and this action is called pattern recognition.
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Uses of speech recognition:
  • Google Voice: Google voice is a service that allows you to search and ask questions on your computer, tablet, and phone.
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  • Car Bluetooth: For cars with Bluetooth or HandsFree phone pairing you can use voice recognition to make commands such as "call my Friend" to make calls without taking your eyes off the road.
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  • Home appliances: We can also use speech recognition software in homes and business.
  • Siri: Apple's Siri is another good example of voice recognition that helps answer questions on Apple devices.
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Advantages:
  • Voice recognition technology can quickly turn your spoken word into written text.
  • This is useful for people with visual impairments and those with physical problems that make typing on a keyboard difficult.
  • In organisations, it increases productivity, reduces costs and errors.
Disadvantages:
  • System don't work so well if there is a lot of background noise.
  • Voice recognition may not be capable of choosing the correct meaning. For example, it cannot always differentiate between homonyms, such as "their" and "there".
  • It may also have problems with slang, technical words and acronyms.