I'm on a Mac and I found the easiest way to run & use local models is Ollama as it has a rest interface: https://github.com/ollama/ollama/blob/main/docs/api.md
I just have a local script that pulls the audio file from Voice Memos (after it syncs from my iPhone), runs it through openai's whisper (really the best at voice to speech; excellent results) and then makes sense of it all with a prompt that asks for organized summary notes and todos in GH flavored markdown. That final output goes into my Obsidian vault. The model I use is llama3.1 but haven't spent much time testing others. I find you don't really need the largest models since the task is to organize text rather than augment it with a lot of external knowledge.
Humorously the harder part of the process was finding where the hell Voice Memos actually stores these audio files. I wish you could set the location yourself! They live deep inside ~/Library/Containers. Voice Memos has no export feature, but I found you can drag any audio recording out of the left sidebar to the desktop or a folder. So I just drag the voice memo into a folder my script watches and then it runs the automation.
If anyone has another, better option for recording your voice on an iPhone, let me know! The nice thing about all this is you don't even have to start / stop the recording ever on your walk... just leave it going. Dead space and side conversations and commands to your dog are all well handled and never seem to pollute my notes.