What's actually happening when Spring AI's `TranscriptionModel` converts speech to text?

The audio is sent to a specialized speech-to-text model (e.g. Whisper), which is architecturally different from a chat LLM — it's trained specifically to map an audio waveform to a text transcript, not to reason or converse. Spring AI wraps this behind the same consistent abstraction pattern as `ChatModel`, so calling it fits the same mental model as a chat call.