If you prefer an existing webapp over an elisp function, https://huggingface.co/spaces/ndurner/oai_chat https://huggingface.co/spaces/ndurner/oai_chat. Choose

If you prefer an existing webapp over an elisp function, https://huggingface.co/spaces/ndurner/oai_chat https://huggingface.co/spaces/ndurner/oai_chat. Choose Whisper as the model, upload your 25 MB chunks, hit Send, choose GPT-4 Turbo, ask it to clean up, hit Send. Then, hit the Download button (hidden away on the very bottom). Helpful fact: Whisper works on 16 KHz sampling behind the scenes, so can make your recording smaller by downsampling to 22 KHz, mono. AAC is supported, and commenters to the web say Whisper is pretty robust so it doesn‘t have do be hi-fi - just so that you can make a split at the beginning of the QA session perhaps, if you can‘t fit it into one 25 MB chunk right away.