# Choosing text or voice for a simulation

> Match the simulation's mode to the channel the skill is used in on the job, and weigh what a voice session costs.

- Canonical: https://docs.devlin.ai/design-guidance/choosing-text-or-voice

A simulation runs as a text conversation or a spoken voice conversation. Choose the mode the learner will use on the job, so they practice under the same cues and pressure.

## Match the channel
- **Phone, video or face-to-face conversation: voice.** Tone, pace and interruptions are part of the skill. A rep who handles angry callers by phone should practice out loud.
- **Chat, email, tickets or messaging: text.** Wording, structure and response time are the skill. A support agent who answers refund requests in chat should practice in text.
- **Mixed channels: the one where failure costs more.** If an account manager emails most of the time but loses deals on calls, practice the calls.

When you cannot tell which channel the skill is used in, ask before you build. Otherwise make the choice and write down the reason in one line, for example "Voice, since reps handle these calls by phone."

## What voice costs
Voice is charged at 120 credits per minute of session time, on top of the credits for the character's replies. Every voice session has a length cap: 5 minutes by default, adjustable from 1 to 25 minutes. A session only starts when the workspace balance covers a full-length session.

Cost matters most when seat time is long or the audience is large. Multiply the expected session length by the number of learners and attempts to estimate the budget. If voice is the right channel but the budget is tight, keep sessions short and focused rather than switching to text: practicing a phone skill in text removes much of what makes it hard. See [Seat time, scope, and pacing for simulations](https://docs.devlin.ai/design-guidance/seat-time-and-scope).

## Related
- [Setting up voice for a simulation or coach](https://docs.devlin.ai/voice/set-up-voice)
- [Letting learners switch between text and voice](https://docs.devlin.ai/voice/text-and-voice-mode-switching)