How the TTS engine works

[pcrx]

I'm not sure if this is the right forum for this, but there was no general inquiries section.

I am a developer for a pharmacy, as such HIPAA prevents us from disclosing patient information in certain ways. My question is, when I generate speech data, is that data being sent to Cepstral servers for processing? Or is the speech staying on my system. Also, would the save to file feature function any differently if the answer is yes.