Voices you choose, and voices you copy
Settings has a Voice tab: three speaking voices to hear and pick, and room to copy a voice from a minute of audio.
Three voices
Bella, Michael and Emma read your replies aloud. Each has a play button so you can hear it before you pick. The voice model downloads the first time you use it, with a thin bar and no dialog.
Copy a voice
Upload or drop about a minute of one person speaking, name it, and Bandicot keeps the cleanest ten seconds to speak with. A passage to read is there if you want to record one, in English or Spanish.
Recordings that are too short, too quiet or distorted get one plain line saying why. Copied voices stay on this Mac, and you can remove any of them.