voice_settings is an object sent in the handshake frame to configure provider-specific parameters:
Telnyx Natural
| Parameter | Type | Default | Description |
|---|---|---|---|
voice_speed | float | 1.0 | Speech rate. Values > 1 are faster. |
Telnyx NaturalHD
| Parameter | Type | Default | Description |
|---|---|---|---|
voice_speed | float | 1.0 | Speech rate. Values > 1 are faster. |
Telnyx Ultra
| Parameter | Type | Default | Description |
|---|---|---|---|
voice_speed | float | 1.0 | Speech rate. Values > 1 are faster. |
language_boost | string | ā | Target language |
volume | float | ā | Volume level |
emotion | string | ā | Emotion: neutral, happy, sad, angry, fearful, disgusted, surprised |
Telnyx Qwen3TTS
| Parameter | Type | Default | Description |
|---|---|---|---|
language_boost | string | "Auto" | Target language. Accepted: Auto, English, Chinese, French, German, Italian, Japanese, Korean, Portuguese, Russian, Spanish, or ISO codes (en, zh, etc.) |
Azure Speech
| Parameter | Type | Default | Description |
|---|---|---|---|
language_code | string | "en-US" | Language code |
text_type | string | "text" | Input type: text or ssml |
effect | string | ā | Audio effect: eq_car or eq_telecomhp8k |
gender | string | ā | Voice gender filter: Male or Female |
AWS Polly
| Parameter | Type | Default | Description |
|---|---|---|---|
language_code | string | ā | BCP-47 language code |
output_format | string | ā | Audio format override |
engine | string | "standard" | Polly engine: standard, neural, generative, long-form |
text_type | string | "text" | Input type: text or ssml |
lexicon_names | array | ā | Pronunciation lexicon names |
Minimax
| Parameter | Type | Default | Description |
|---|---|---|---|
speed | float | ā | Speech rate |
vol | float | ā | Volume |
pitch | integer | ā | Pitch adjustment |
language_boost | string | ā | Language emphasis |
Inworld
| Parameter | Type | Default | Description |
|---|---|---|---|
language_code | string | ā | Language code |