Figure 1. Roll Your Own Speech Apps.
This simple class diagram lays out the key aspects of building a speech-based application using SAPI 5.1 or 5.3, along with the Windows Presentation Foundation (WPF). The native speech capabilities of .NET and WPF aren't well known, but they are powerful, and can enable you to create more powerful apps with much less code and effort than has historically been the case when creating speech-based applications.