Does Google or other "voice to text" need internet?

[Android Central Question]

I love voice to text for emails and texts as it is much faster than swiping, etc. However, when I'm in my basement office or any location where my data is lagging, it works terrible. I assume it uses ONLY data because my WiFi connection makes no difference. My voice to text ONLY works well when I'm somewhere that I have a good 3-4 bar 4G connection. I HAVE to assume that everything I say is sent to a Google server, translated, then sent back to my phone. This sounds silly, but the evidence is overwhelming. Bad cell data connection = poor voice to text 100% of the time. Is there a way around this, so that I don't need internet OR cell data for the translation part? Perhaps a specific app to replace Google's or Samsung's voice to text apps?

 

[Rukbat]

The only other good one is Dragon Naturally Speaking, using their "Remote Mic" app on your phone and the DNS program on your PC.