static string ConvertTextToWav(string text, string fileName)
{
var baseDir = Path.Combine (Environment.GetFolderPath (Environment.SpecialFolder.Personal), "..");
var tmpDir = Path.Combine (baseDir, "tmp");
string ttsFilePath = Path.Combine (tmpDir, fileName);
flite_init ();
flite_text_to_speech (text, register_cmu_us_kal (), ttsFilePath);
return ttsFilePath;
}