Hold to talk, or press once to start?
Every dictation key does both: hold it to record only while it is down, or start hands-free (how depends on the key) and press it once more to stop.
There is no separate setting for this. Whichever key you chose under Settings → General already does both, and Dictate Safe tells which one you meant from how you press it.
#Hold to talk
- Hold your dictation key down.
- Speak.
- Let go.
Recording stops the moment you release the key, like a walkie-talkie.
#Hands-free with a key combination, or F9
On Windows, with F9 (the default) or a combination such as Ctrl+Shift+D, and on a Mac with a combination such as ⌘ ⇧ D, tap the key quickly instead of holding it. Recording keeps going after you let go, so you can talk with your hands off the keyboard. Press the same key again to stop.
#Hands-free with a single key
Fn, Right ⌘, Right ⌥ and Right ⇧ work a little differently, because a stray tap of a key like Fn happens by accident. Tap it twice, quickly, and hands-free turns on. Press it once more to stop. A single tap on its own starts nothing that keeps running: the recording it began stops again a moment later.
#Which one to use
Hold to talk suits short bursts: a quick reply, a search box, one line in a chat. Hands-free suits longer dictation, such as drafting an email or a long prompt, where holding a key the whole time would be uncomfortable.
Hands-free recording has no time limit. If you would rather it stopped on its own, set one under Settings → Typing → Stop automatically after: 1, 2, 5 or 15 minutes. It is set to Never unless you change it.