OpenAI’s Whisper
is one of the best open-source speech models around. Out of the box, whisper-large-v3-turbo hits about 8% word error rate (WER) on general English tests like LibriSpeech. But point it at radiology reports, esports commentary, court audio, or factory SOPs and that number can spike to 30-50%. The model just hasn’t seen enough of those niche terms in training.
You can fix this. Fine-tuning Whisper on a small set of domain audio, as little as one to three hours, with LoRA adapters cuts domain-term WER by 30-60%. The full training run fits on a single consumer GPU with 12-16 GB of VRAM. It takes a couple of hours and yields an adapter file under 100 MB. Below is the full path from data prep to deployment.
Botmonster Tech



