SignalWire DocsUse ai.languages to configure the spoken language of your AI Agent, as well as the TTS engine, voice, and fillers.
An array of objects that accept the following properties.
Name of the language (“French”, “English”, etc). This value is used in the system prompt to instruct the LLM what language is being spoken.
Set the language code for ASR (Automatic Speech Recognition) (STT (Speech-to-text)) purposes. By default, SignalWire uses Deepgram’s Nova-3 STT engine, so this value should match a code from Deepgram’s Nova-3 language codes table.
openai_asr_engine parameter, you must select a code supported by that engine.String format: <engine id>.<voice id>.
Select engine from gcloud, polly, elevenlabs, or deepgram. Select voice from TTS provider reference.
For example, "gcloud.fr-FR-Neural2-B".
See voice usage for more details.
Enables emotion for the set TTS engine. This allows the AI to express emotions when speaking. A global emotion or specific emotions for certain topics can be set within the prompt of the AI.
Valid values: auto
Cartesia TTS engine.An array of strings to be used as fillers in the conversation when the agent is calling a SWAIG function. The filler is played asynchronously during the function call.
The model to use for the specified TTS engine (e.g. arcana). Check the TTS provider reference for the available models.
An array of strings to be used as fillers in the conversation. This helps the AI break silence between responses.
speech_fillers are used between every ‘turn’ taken by the LLM, including at the beginning of the call. For more targed fillers, consider using function_fillers.The speed to use for the specified TTS engine. This allows the AI to speak at a different speed at different points in the conversation. The speed behavior can be defined in the prompt of the AI.
Valid values: auto
Cartesia TTS engine.TTS engine-specific parameters for this language.
The similarity slider dictates how closely the AI should adhere to the original voice when attempting to replicate it.
The higher the similarity, the closer the AI will sound to the original voice.
Valid values range from 0.0 to 1.0.
Only works with the ElevenLabs TTS engine.
The stability slider determines how stable the voice is and the randomness between each generation.
Lowering this slider introduces a broader emotional range for the voice.
Valid values range from 0.0 to 1.0.
Only works with the ElevenLabs TTS engine.
An array of strings to be used as fillers in the conversation and when the agent is calling a SWAIG function. Deprecated: Use speech_fillers and function_fillers instead.
The engine to use for the language. For example, "elevenlabs". Deprecated. Set the engine with the voice parameter.
voice stringsCompose the voice string using the <engine id>.<voice id> syntax.
First, select your engine using the gcloud, polly, elevenlabs, or deepgram identifier.
Append a period (.), and then the specific voice ID (for example, en-US-Casual-K) from the TTS provider.
Refer to SignalWire’s Supported Voices and Languages
for guides on configuring voice ID strings for each provider.
SignalWire’s cloud platform integrates with leading text-to-speech providers. For a comprehensive list of supported engines, languages, and voices, refer to our documentation on Supported Voices and Languages.
SWML will automatically assign the language (and other required parameters) to the defaults in the above table if left unset.
This example uses ai.language to configure a specific English-speaking voice from ElevenLabs.
SWML will automatically assign the language (and other required parameters) to the defaults in the above table if left unset.
This example uses ai.language to configure multiple languages using different TTS engines.
Configure different stability and similarity values for each language using languages[].params: