whisper is an STT application that stems from openAI afaik, but it's open source at this point.

i wrote a little guide on how to install it on a server with an NVidia GPU and hw acceleration and integrate it into your homeassistant after. https://a.lemmy.dbzer0.com/lemmy.dbzer0.com/comment/5330316

it's super fast with a GPU available and i use those little M5 ATOM Echo microphones for this.