We are encountering limitations with language and dialect selection when using multilingual voices in Smart Assist. Our company has a particular focus on Australian English voices, but currently, we are limited to a small selection. We would like to expand this list by leveraging the capabilities of MS Azure's multilingual voices to select the Australian English dialect for each.

For example, currently in Smart Assist, selecting English (Australian) is currently unavailable for the voice 'en-US-AvaMultilingualNeural', so we would like this issue fixed - but we would also like to be able to choose English (Australian) for all the multilingual voices as well, like 'zh-CN-XiaoxiaoMultilingualNeural'. Essentially, any multilingual language should have options to select languages and dialects but this feature currently seems broken.

Currently, the list does include entries such as "Jenny-Polyglot (EN - AU - Female)", so it looks like an attempt was made some time ago when JennyMultilingualNeural was the only multilingual voice available from Azure, but currently all of the polyglot selections revert to the default en-US voice.

We would like to request access to the following multilingual voices with the ability to select dialects (like en-AU) and (if possible) be able to apply SSML features such as prosody and speaker styles. I've included the language codes in the hopes of speeding things up:

We appreciate your consideration of this feature request, as it will greatly enhance our multilingual voice capabilities, especially for Australian English but for all of our multilingual needs where we need a consistent voice character.