As noted by Dictionary.com.

Main Entry: voice recognition
Function:noun
Definition: a technology designed to recognize and respond to spoken commands through digitization and algorithm-based programming; also called speech recognition
Example: Voice recognition is in use on some telephone and computer systems.

speech recognition / voice recognition

<application> (Or voice recognition) The identification ofspoken words by a machine. The spoken words are digitized (turned into sequence of numbers) and matched against coded dictionaries in order to identify the words.
Most voice recognition systems must be 'trained,' requiring samples of all the actual words that will be spoken by the user of the system. The sample words are digitized, stored in the computer and
used to match against future words. More sophisticated systems require voice samples, but not of every word. The system uses the voice samples in conjunction with dictionaries of larger vocabularies to match the incoming words. Yet other systems aim to be 'speaker-independent', i.e. they will
recognize words in their vocabulary from any speaker without training.

Voice Recognition - a definition

Another variation is the degree with which systems can cope with connected speech. People tend to run words together, e.g. 'next week' becomes 'neksweek' (the 't' is dropped). For
a voice recognition system to identify words in connected speech it must take into account the way words are modified by the preceding and following words. (As understood by voice recognition)
It has been said (in 1994) that computers will need to be something like 1000 times faster before large vocabulary (a few thousand words), speaker-independent, connected speech voice recognition will be feasible. With the advent of Intel Pentium and Core processors, computers are now fast enough to truly take advantage of voice recognition technology.