I\'m working on a project in Linux (KUbuntu) using Mono and Monodevelop. I want to use the System.Speech library, which is completely possible with Monodevelop in Unity on W
System.Speech is a part of MSFT's .Net and is dependent on native audio drivers, the TLS engine, etc... and is only available on Windows.
I believe there was some work done in Mono with the Speech namespace 4/5 years ago, but there is nothing in this namespace in the current releases.
You would need to look at third party speech libs on Linux and write some C# wrappers for them if they are not currently available.