I have been having issues with the agents not being able to correctly spell out email usernames lately. For example, the caller will spell out “classroom” and the agent will repeat “c l a s s r o 0 m” instead or completely misspell a word. I use both vapi and eleven labs voices and they were doing great until about a week ago. I had this issue in the past but it was resolved by choosing the right voice. Has there been some sort of update or something I should look for that has changed?

Lately it sounds like the voice/TTS isn’t accurately spelling things out that usually points to a change in how the voice model is handling phonetics, not your prompt logic. Since both Vapi and ElevenLabs voices were fine before and now aren’t, it’s very likely one of their recent voice model updates changed how they render spelled‑out text. Sometimes certain voices handle sequences (like letter‑by‑letter) poorly after an update. A quick way to confirm is to try a different voice again if it spells correctly, then the issue is specific to that voice model. If all voices are now doing it, there’s likely been a broader update on the TTS side that changed phonetic handling. If you tell me which voices you’re currently using, I can suggest ones that reliably spell out letters correctly. @lotalop

Hi, I am currently using Vapi's Nico, Emma, and an eleven labs voice as well @User

That confirms it’s a phonetic issue with those specific voices Nico, Emma, and the ElevenLabs voice likely changed how they handle spelled-out letters in a recent update. A quick fix is to test alternative voices known for accurate letter-by-letter spelling. I can suggest a few reliable ones if you want. @lotalop

Sure

Let's connect @lotalop

Hi, apologies for the delay.