### Answer For Twilio, CPS changes can take up to 10 minutes to apply. [(1) ]() | Provider | Default CPS | Maximum CPS | Notes | |----------|-------------|-------------|-------| | Twilio | 1 | 5 | Changes take up to 10 minutes | | Telnyx | 1 | 16 | Instant updates | | Custom Telephony | 1 | Concurrency ÷ 20 | Based on your concurrency limit | If it's been more than 10 minutes and your Twilio CPS still hasn't updated, this may indicate an issue beyond the normal propagation delay. You might want to: - Verify the change was saved correctly in your settings - Try refreshing your dashboard - Reach out to support if the issue persists

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

​ To learn more, see the sources I considered: [[1] Outbound Calls (Make Calls)](https://docs.retellai.com/deploy/outbound-call) ​

### Answer To reduce costs from Cartesia (your current TTS voice engine) , you can switch to a different voice provider. Retell AI supports multiple TTS providers, and you can change your agent's voice in the agent settings. Available voice options include: [(1) ]() - ElevenLabs voices (with models like

eleven_turbo_v2

,

eleven_flash_v2

,

eleven_flash_v2_5

, etc.) - OpenAI voices (e.g.,

openai-Alloy

) - Deepgram voices (e.g.,

deepgram-Angus

) - PlayHT voices (added as an alternative provider) [(2) ]() To change your voice: 1. Go to your agent settings in the dashboard 2. Select a different

voice_id

from another provider 3. Optionally adjust the

voice_model

setting for providers like ElevenLabs [(1) ]() Pricing considerations: - ElevenLabs Flash v2/v2.5 models offer "blazing fast latency" with medium quality [(2) ]() - PlayHT is priced at $0.08/min for the voice engine - You can also set

fallback_voice_ids

from different providers for reliability [(1) ]() If you want the lowest latency option, ElevenLabs Flash models may be worth considering. Check the dashboard to compare current pricing for each voice provider.

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

​ To learn more, see the sources I considered: [[1] Get Voice Agent](https://docs.retellai.com/api-references/get-agent) [[2] Platform Changelogs | Retell AI](https://www.retellai.com/changelog) ​

### Answer I don't have specific cost-per-minute pricing comparisons for each voice provider in my available sources. The documentation shows the available

voice_model

options [(1) ]() : - **ElevenLabs**:

eleven_turbo_v2

,

eleven_flash_v2

,

eleven_turbo_v2_5

,

eleven_flash_v2_5

,

eleven_multilingual_v2

- **Cartesia**:

sonic-2

,

sonic-3

,

sonic-turbo

- **OpenAI**:

tts-1

,

gpt-4o-mini-tts

- **MiniMax**:

speech-02-turbo

To find the most cost-effective option, I'd recommend checking the pricing page in your Retell dashboard or visiting [Contact Sales]() for detailed pricing breakdowns. Would you like me to try providing a general answer based on common knowledge about TTS pricing, or would you prefer to check the dashboard directly?

​ To learn more, see the sources I considered: [[1] Create Voice Agent](https://docs.retellai.com/api-references/create-agent) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer I don't have information in my sources about which voice provider offers the "best" cost or quality trade-off. The documentation lists the available

voice_model

options [(1) ]() : - **ElevenLabs**:

eleven_turbo_v2

,

eleven_flash_v2

,

eleven_turbo_v2_5

,

eleven_flash_v2_5

,

eleven_multilingual_v2

- **Cartesia**:

sonic-2

,

sonic-3

,

sonic-turbo

- **OpenAI**:

tts-1

,

gpt-4o-mini-tts

- **MiniMax**:

speech-02-turbo

However, pricing details and quality comparisons aren't documented in my available sources. Check out these potentially useful sources: - [Create Voice Agent]() - [Update Voice Agent]() For specific pricing, your Retell dashboard should show current costs per provider. Would you like a general answer based on common knowledge about TTS pricing instead?

​ To learn more, see the sources I considered: [[1] Create Voice Agent](https://docs.retellai.com/api-references/create-agent) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer --- For Twilio, CPS changes can take up to 10 minutes to propagate. [(1) ]() If it's been significantly longer and the change still hasn't applied, here are some troubleshooting steps: 1. Verify the change was saved – Double-check in your Retell dashboard that the new CPS value is actually reflected in your settings 2. Confirm you're within limits – Twilio's maximum CPS is 5 3. Implement retry logic – If you're hitting throttling, use exponential backoff:

javascript
// Example retry logic
const maxRetries = 3;
let retryDelay = 1000; // Start with 1 second
for (let i = 0; i < maxRetries; i++) {
  try {
    await makeCall() ;
    break;
  } catch (error) {
    if (error.code === 'rate_limited') {
      await sleep(retryDelay) ;
      retryDelay *= 2; // Exponential backoff
    }
  }
}

If the issue persists after verifying these steps, you may want to reach out to support: - Visit [Contact Sales]() - Check [)

​ To learn more, see the sources I considered: [[1] Outbound Calls (Make Calls)](https://docs.retellai.com/deploy/outbound-call) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.