> ## Documentation Index
> Fetch the complete documentation index at: https://docs.botcadence.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Voice Lab

> Preview TTS providers, models, voices, and delivery settings before deploying a voice agent

**Build → Voice Lab** lets you hear how your AI Agent will sound. Enter a short script, choose a voice service and voice, play a sample, and compare two choices with **A/B Testing**. A voice service turns written words into spoken audio.

## Preview a voice

**1. Open Voice Lab**

From a project, select **Build → Voice Lab**. Wait for the project voice configuration to load before choosing a provider.

**2. Enter a representative script**

Use a short sentence that includes the names, numbers, abbreviations, or language your agent will say in production. The page's script field is labeled **Enter a short script to preview this voice...**.

**3. Configure the sample**

Choose a TTS provider, model, language, and voice. If the provider supports it, set the model-specific voice options or enter a custom voice ID.

**4. Generate and listen**

Run the test and listen for pronunciation, latency, pacing, and natural turn endings. Repeat with a few scripts rather than choosing from one sentence alone.

## Compare two configurations

Enable **A/B Testing** when you are deciding between providers, models, or voices. Configure Voice A and Voice B with the same script, generate each sample, and compare intelligibility, emotional fit, speed, and cost/latency trade-offs. A comparison is only useful when the text and playback conditions are the same.

## Settings that matter

* **Provider and model** determine the synthesis engine, available languages, voice catalog, and model-specific controls.
* **Voice** selects a catalog voice. A **Custom Voice ID** can be used when your provider exposes a custom or cloned voice.
* **Language** affects pronunciation and the language-specific catalog.
* **Speed, volume, and emotion** are available only when the selected provider/model supports them; keep them consistent with the tone in the workflow prompt.

> [!NOTE]
>
> Voice Lab previews audio; it does not replace an end-to-end call test. The final behavior also depends on speech-to-text, the LLM, interruptions, welcome-message settings, and the workflow's handover and timeout rules.

## Move from preview to workflow

After choosing a configuration, open [Workflows](https://docs.botcadence.com/docs/build/workflows.md), select the relevant Voice Agent node, and update the **Voice** tab. Review the STT, TTS, and LLM settings together. Set **Who Speaks First**, the optional welcome message, interruption behavior, and node timeout in the **General** tab where applicable.

Then run the full flow in [Playground](https://docs.botcadence.com/docs/build/playground.md), connect it to a test [inbound](https://docs.botcadence.com/docs/deploy/inbounds.md) or Web Voice channel, and verify the call transcript in [Operate → Conversations](https://docs.botcadence.com/docs/operate/conversations.md).

## Troubleshoot preview failures

* **No providers or voices** — wait for configuration to load and confirm the project has access to voice settings.
* **Provider loads but playback fails** — check that both a provider and voice (or custom voice ID) are selected, then retry with a shorter script.
* **Voice sounds wrong in production** — confirm the workflow uses the same provider, model, voice, language, and voice options that you tested in Voice Lab.
* **The new voice is not live** — save and publish the workflow attached to the deployed voice surface.


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