Hello @Dupont-Viel, Jean-François !
Welcome to Microsoft QnA!
There is not a document saying that
When you select the Standard Tier you pay for that Tier based on pricing
Have a look also on Azure Pricing Calculator
https://azure.microsoft.com/en-us/pricing/calculator/
|Text to Speech(per character billing)|Neural|Real-time & batch syntheis: $16 per 1M
characters
Long audio creation: $100 per 1M characters|
| -------- | -------- | -------- |
||
I hope this helps!
Kindly mark the answer as Accepted and Upvote in case it helped!
Regards