For now, a larger amount of speech-related information is at: User Interface Basics: Speech
Speech recognition is a trending technology. At the time of this writing, some programs such as Apple's Siri, Google's “OK Google”/“Google Now”, Microsoft's Cortana (named after a character from the “Halo” series of video games), and Sirius (open source, and, at the time of this writing, apparently usable with Ubuntu) are developing rapidly. Amazon may also have an offering.
This site tends to focus more on established knowledge. With some of the very latest technical advancements, details are likely to be quite subject to change, and so there may not be a tremendous hurry to rush information onto this page. As technologies seem to be stable, and useful information is encountered, details are likely to be getting added.