Speech Recognition

"Automatic speech recognition (ASR) is one of the fastest growing and commercially most promising applications of natural language technology. Speech is the most natural communicative medium for humans in many situations, including applications such as giving dictation; querying database or information-retrieval systems; or generally giving commands to a computer or other device, especially in environments where keyboard input is awkward or impossible (for example, because one’s hands are required for other tasks)."
 - From Linguistic Knowledge and Empirical Methods in Speech Recognition. By Andreas Stolcke. (1997). AI Magazine 18 (4): 25-32.

Today, when we call most large companies, a person doesn't usually answer the phone. Instead, an automated voice recording answers and instructs you to press buttons to move through option menus. Many companies have moved beyond requiring you to press buttons, though. Often you can just speak certain words (again, as instructed by a recording) to get what you need. The system that makes this possible is a type of speech recognition program -- an automated phone system.

You an also use speech recognition software in homes and businesses. A range of software products allows users to dictate to their computer and have their words converted to text in a word processing or e-mail document. You can access function commands, such as opening files and accessing menus, with voice instructions. Some programs are for specific business settings, such as medical or legal transcription.

People with disabilities that prevent them from typing have also adopted speech-recognition systems. If a user has lost the use of his hands, or for visually impaired users when it is not possible or convenient to use a Braille keyboard, the systems allow personal expression through dictation as well as control of many computer tasks. Some programs save users' speech data after every session, allowing people with progressive speech deterioriation to continue to dictate to their computers.
... from How Things Work

Image from Wikipedia.