Speech is an effective and natural way for people to interact with applications, complementing or even replacing the use of mice, keyboards, controllers, and gestures. A hands-free, yet accurate way to communicate with applications, speech lets people be productive and stay informed in a variety of situations where other interfaces will not.

The Microsoft Speech Platform SDK 11 includes both managed-code and native-code application programming interfaces (APIs).

The Microsoft.Speech managed-code namespaces provide you with easy access to the advanced speech recognition and speech synthesis technologies supported by the Microsoft Speech Platform Runtime 11. The functionality that the managed code APIs expose is a subset of the native-code APIs and will satisfy the majority of speech application scenarios.

The native-code APIs implement all the low-level details needed to control and manage the real-time operations of various speech engines.

You do not need to create your own engines for speech recognition and text-to-speech because you can download and install any of the 26 language packs (speech engines) for speech development. See What's New in the Microsoft Speech Platform SDK 11.

Speech recognition allows users to interact with and control your applications by speaking. Using the APIs in the Speech Platform SDK 11, you can acquire and monitor speech input, create speech recognition grammars that produce both literal and semantic recognition results, capture information from events generated by the speech recognition, and configure and manage speech recognition engines. See Speech Recognition (Microsoft.Speech).

The speech synthesis APIs in the Speech Platform SDK 11 will have your application talking with just a few lines of code. You get control over many aspects of voice expression, including volume, speaking rate, word emphasis, pitch contour, and other attributes of speech. See Speech Synthesis (Microsoft.Speech).

For both speech recognition and speech synthesis, you get your choice of authoring formats. You can author content programmatically, using the members of the Microsoft.Speech namespaces. Or you can create industry-standard, XML-format speech documents for consumption by the Speech Platform Runtime 11. You can even alternate authoring formats based on your preferences and combine programmatic content with XML-format content.

The Speech Platform SDK 11 provides tools that you can use to debug and tune grammars that you create for use with the Speech Platform Runtime 11. The functionality of the Microsoft Grammar Development Tools includes grammar validation, phrase generation, confusability detection, batch-mode simulated speech recognition, analysis of simulated recognition results including graphs, and grammar compiling. The Grammar Development Tools will help you to identify problem areas that are hard to detect through standard speech application testing, and to identify problems earlier in the application development life cycle. See Microsoft Grammar Development Tools.

The Speech Platform SDK 11 can significantly reduce the amount of work necessary to implement speech in applications for Windows Server. By providing access to the Speech Platform Runtime 11 and engines for speech recognition and speech synthesis, the Speech Platform SDK 11 gives you the tools to create sophisticated speech applications for Windows Server while shortening development cycles and reducing development costs.