Voices and speech

The SIMCOAI voices by name, the SIMCOAI speech engines that listen, and what to change when either is not working well.

Voices

The SIMCOAI voices

These are the voices your callers hear. The trade is the same one every time: a faster voice starts speaking sooner, a richer voice sounds less like a machine. Which are available depends on your plan.

VoiceWhat it is for
SIMCOAI Voice RapidThe quickest to start speaking. Where the very first word matters more than anything else.
SIMCOAI Voice NaturalThe everyday speaking voice, and what answers your phone by default. Fast enough that a caller is never left waiting.
SIMCOAI Voice StudioRicher and more expressive, for businesses where the greeting is the first impression.
SIMCOAI Voice SignatureThe widest emotional range available, and the slowest to start. The one that sounds least like a machine.
Speech

The SIMCOAI speech engines

How SIMCOAI understands what a caller said - including when they have finished saying it, which is what stops the assistant talking over somebody.

EngineWhat it is for
SIMCOAI Speech LiveFollows the rhythm of a conversation, so the assistant knows a caller has finished rather than waiting for a pause. Used on live calls.
SIMCOAI Speech PreciseHighest-accuracy transcription, for getting a name, an address or a reference exactly right.
SIMCOAI Speech StandardGeneral purpose, for recorded messages and anything not on a live call.
As with the models, these are SIMCOAI configurations rather than engines SIMCOAI built - see AI models for what that means, and the privacy policy for who processes what.
Choosing

Picking a voice

You pick one in the dashboard and hear a preview before committing it to a live line.

  1. Open your call settingsVoice options sit alongside greeting and speech settings.
  2. PreviewListen before you apply. A voice that reads well can still sound wrong for your brand.
  3. ApplyThe voice takes effect on the next call, not mid-call.
  4. Test on a real callPreview text is short. A real conversation exposes pacing you will not hear in a sample.
Random

Rotating the voice

You can let SIMCOAI vary the voice rather than always using the same one.

SettingBehaviour
Fixed voiceEvery call uses the voice you selected
RotatingSIMCOAI picks from the voices available on your plan, once per call
Careful. Rotating needs at least two voices available to do anything. With one it behaves identically to a fixed voice.
Hearing

When a caller is hard to understand

Speech settings affect how quickly SIMCOAI decides a caller has finished speaking. That trade-off is real: react too fast and you interrupt, too slow and the call feels sluggish.

  • Noisy environments — callers on speakerphone or in a workshop produce more interim results and more false endpoints.
  • Long pauses — callers reading an order number aloud often pause mid-sequence.
  • Accents and speed — test with voices representative of your actual customers, not just your own.
Judging

Was it any good?

Every call records measurable signals rather than leaving you to guess. See call quality signals for first-reply latency, interruption handling and finish reasons.