Hello @MikeC
I think you are mentioning the audio content creation - https://speech.microsoft.com/audiocontentcreation
The document is here: https://learn.microsoft.com/en-us/azure/cognitive-services/speech-service/how-to-audio-content-creation
You can try the voice one by one to see which one is as your need.
I hope this helps! Please let us know if you need more help.
Regards,
Yutong
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