@佳鑫 朱 Welcome to Microsoft Q&A Forum, Thank you for posting your query here!
The Batch synthesis API for text to speech is generally available. More info here.
The regions that support for Speech service features such as speech to text, text to speech, pronunciation assessment, and translation. The geographies are listed in alphabetical order in this article:
In the above table, the regions which are numbered with 3 doesn't support Batch Synthesis API.
More info here.
If you have any follow-up questions, please let me know. I would be happy to answer.
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