Speak

Speak settings control how assistant text becomes audio. Use this section for speak.* runtime options and deployment settings related to text-to-speech, voices, pronunciation, ambient audio, and speech delivery.

Speak settings are used by voice-capable deployments: Phone Call, Web Widget with spoken responses, and Web App / SDK with spoken responses. Text-only channels do not use speak configuration.

Configure it

Open your assistant, select Configure Assistant, then open Deployments. Speak settings appear in the Voice Output step for each deployment that supports spoken responses.

Area	What it controls
Text-to-Speech	Provider, credential, model, voice, language, and speech synthesis behavior.
Pronunciation	How dates, times, numbers, addresses, URLs, acronyms, and domain terms are spoken.
Delivery	Pause behavior, conjunction boundaries, and optional ambient audio.

Configuration pages

Text-to-Speech

Choose the provider, voice, model, language, pronunciation, and speech delivery settings.

Custom TTS

Connect a custom WebSocket speech synthesis provider with DSL rules.

Recommended starting point

Area	Start with
TTS	A low-latency streaming voice that supports the assistant’s primary language.
Pronunciation	Enable dictionaries for numbers, currency, dates, times, URLs, and domain terms that users will hear often.
Prompt	Short spoken responses, usually one or two sentences.

Tune speak settings by listening to full conversations in the target channel. A voice that sounds good in a browser preview can still sound unclear over phone audio.

Runtime overrides

You can override speak settings for a single outbound phone call by passing speak.* or speaker.* keys in CreatePhoneCallRequest.options. Runtime overrides do not update the saved deployment.

{
  "options": {
    "speak.voice.id": "VOICE_ID_PLACEHOLDER",
    "speak.language": "en",
    "speak.model": "sonic-2",
    "speak.audio.encoding": "mulaw",
    "speak.audio.sample_rate": 8000,
    "speaker.conjunction.boundaries": "and<|||>but<|||>or",
    "speaker.conjunction.break": 240
  }
}

Option key	Type	Description
`speak.voice.id`	`string`	TTS voice ID for this call.
`speak.language`	`string`	Output speech language or provider language code.
`speak.model`	`string`	Provider-specific TTS model.
`speak.audio.encoding`	`string`	Output audio encoding when supported by the provider.
`speak.audio.sample_rate`	`number`	Output audio sample rate.
`speak.query_params`	JSON object string	Custom TTS provider query parameters.
`speak.request_rules`	JSON array string	Custom TTS request DSL rules.
`speak.response_rules`	JSON array string	Custom TTS response DSL rules.
`speak.__experimental_controls.speed`	`string`	Provider-specific experimental speed control.
`speak.__experimental_controls.emotion`	`string`	Provider-specific experimental emotion control.
`speak.speed_alpha`	`string`	Provider-specific speed alpha control.
`speak.speed`	`string`	Provider-specific speaking speed.
`speaker.language`	`string`	Speaker normalization language.
`speaker.voice.name`	`string`	Human-readable speaker or voice name.
`speaker.conjunction.boundaries`	`string`	Delimiter-separated words where Rapida can insert pauses.
`speaker.conjunction.break`	`number`	Pause duration at conjunction boundaries in milliseconds.
`speaker.pronunciation.dictionaries`	`string`	Pronunciation dictionary configuration.
`speaker.ambient`	`string`	Ambient audio preset.
`speaker.ambient_volume`	`number`	Ambient audio volume.

Troubleshooting map

Symptom	First place to look
Assistant voice starts slowly	Text-to-Speech model latency and response length
Assistant mispronounces product names or numbers	Text-to-Speech pronunciation dictionaries
Assistant sounds rushed	Conjunction boundaries, pause duration, and prompt response length
Voice sounds poor on phone	Test through Phone Call, not only browser preview

Experience

Configure greeting, idle timeout, error message, and session duration.

Listen

Configure speech-to-text, VAD, noise cancellation, and end-of-speech.

Phone Call Deployment

Configure required voice output for phone calls.

Web Widget Deployment

Configure optional spoken responses in the web widget.

Assistants

Knowledge

LLM Endpoint

Activity & Logs

External Integrations

Credentials

Workspace

Governance

Deployment Options

Configure it

Configuration pages

Text-to-Speech

Custom TTS

Recommended starting point

Runtime overrides

Troubleshooting map

Experience

Listen

Phone Call Deployment

Web Widget Deployment

​Configure it

​Configuration pages

Text-to-Speech

Custom TTS

​Recommended starting point

​Runtime overrides

​Troubleshooting map

​Related

Experience

Listen

Phone Call Deployment

Web Widget Deployment

Configure it

Configuration pages

Recommended starting point

Runtime overrides

Troubleshooting map

Related