On Windows and Mac OS X, users have long grown accustomed to controlling the PC not just with the keyboard and mouse, but by voice. For several years, Linux has been playing catch-up. The nonprofit association "Simon Listens" [1], founded by Franz Stieger, is the driving force behind the Simon speech recognition software.

The application, originally developed to give people with special needs access to barrier-free PC use, has been around for several years. The association still pursues this goal, but the developers have discovered some additional uses for the software, including verbal control systems that facilitate the use of modern communication technologies by the elderly or allow humans to control robots, wheelchairs, and lifts. However, if you are looking to dictate text to Simon, you will not be happy with the results and will need to look elsewhere.

Simon became an official KDE Project in April 2012 [2] and thus uses the KDE infrastructure. The speech recognition software follows the client-server model, consisting of several components and drawing on a variety of other programs, such as the CMU Sphinx voice recognition toolkit [3], the Julius speech recognition engine [4] with the Hidden Markov Model Toolkit (HTK) [5], and the Hadi-Bomp pronunciation dictionary [6]. The application components include the Simon front end, the Simon daemon (Simond), the Simon Acoustic Modeler (sam), and the Simon Sample Collector (SSC).

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