Agent confirming name and email are garbling/slurring words

Support Help
1

Hello Omar,

call ID: call_e840120f9455d8f8d324df14dde
call ID: call_5d212b29101600844b7e8916747
Call ID: call_0b5441cb295960e56a6b0ed7e1c

these 3 call ids have the issue we are dealing with. The transcription is correct but when the AI repreats back to confirm name/email the pronounctiation is garbled/slurred causing the user to think its not correct. Can we have a solution for this? I have prompted and followed every guid by Retell

2

Thank you for reaching out to Retell AI Support. We’ve received your ticket and our team will respond within 8 hours.

3

Hello,

After reviewing the calls, there are no system errors on any of them, so the garbled/slurred pronunciation appears to be related to the agent’s voice configuration rather than a platform issue.

Here are a few things to try that should improve pronunciation quality for names and emails:

  1. Disable “Normalize for Speech” in your agent settings — this feature preprocesses text before the voice engine and may be interfering with the letter-by-letter spelling format you’re using in your prompt.
  2. Switch the voice model from the multilingual turbo model to the English-optimized model — since your agent is set to English (en-US), the English model generally handles proper nouns and spelling better. You can do this in your agent’s voice settings by selecting the default model.
  3. Set voice speed to 1.0 (currently 0.9) — the slight slow-down uses audio post-processing that can introduce artifacts, especially on short sounds like individual letters.
  4. Prompt adjustment: Instead of spelling letter-by-letter, you could try having the agent confirm names by saying them naturally (e.g., “Just to confirm, your last name is Hawkins — is that correct?”) and only spell it out if the caller says it’s wrong. Voice engines generally pronounce full words much more clearly than individual letters.

I’d suggest trying these one at a time to see which makes the biggest difference.

Regards,
Retell Support Team

4

I removed the dashes and seemed to have help but when spelling by letter it’s fast which is why the dashes were there in the first place. Should I still uncheck normalize for speech?

5

Hello,

You don’t have to make all the modifications that were recommended. You can test them incrementally.

Regards
Retell Support

6

Should I then reintroduce the dashes per letter such as j-d-o-e at gmail dot com?

7

Hello,

Please adjust the settings according to the results of your testing.
You mentioned that removing the dashes made it better in your test, so you can keep them out and move on to trying additional options to improve it further.

Regards
Retell Support