/// <summary>
/// Shut down the background thread.
/// </summary>
internal override void Shutdown()
{
// If the background thread is alive, send it the special
// empty utterance that will make it shut down gracefully.
if (speakingThread != null && speakingThread.IsAlive)
{
Say(null, null, new Vector3(0, 0, 0), null);
Thread.Sleep(600);
}
speakingThread = null;
// Shut down the synthesizer.
syn.Shutdown();
}
