Azure AI Speech HD voices unsupported (2511240019)

[Ryan Forster]

Hi team,

We have had an issue raised by our customer where the following TTS voices are not working when attempting to integrate via Speech To Text:

de-DE-Florian:DragonHDLatestNeural
de-DE-Seraphina:DragonHDLatestNeural

Other voices work fine, it's only these two that we are experiencing problems with. Specifically, it's the following log that we are seeing on our side:

2026-02-05 14:40:15:059369 [INFO]   Received HTTP response [400 Unsupported voice Microsoft Server Speech Text to Speech Voice (de-DE, Seraphina:DragonHDLatestNeural).] in 90 msec for <5de7b470455849eb> [https://westeurope.tts.speech.microsoft.com/cognitiveservices/v1]
Please could you check the configuration on your side and confirm whether you are aware of any issues relating to the above two voices? We have aligned directly with Microsoft Speech Services who have confirmed that they do not see any issues on their side. This is further supported by the fact that the voices can be tested successfully on the Azure Speech Studio website.

Many thanks,

Ryan