Glossary

What is speaker diarization?

Diarization is a machine working out who is speaking when, from the audio alone, and splitting the transcript by speaker automatically. Cast does not do this — you label speakers yourself, which takes a few clicks and never guesses wrong.

Two microphones give two separable tracks and nothing has to be guessed. One shared microphone gives a single blended waveform that no editor can reliably pull apart — which is why Cast asks you to label speakers rather than guess. — One mic each is separable. One shared mic is not — whatever the marketing says.

It is worth knowing the word because tools advertise it, and worth knowing its limits: diarization degrades badly on people talking over each other and on two voices captured by one microphone, which is exactly when you most want it to work.