Since Sept 15th (1 month and thirteen days as I’m writing this post right now), TTS audio generation quality has been notoriously poorer. As you listen to the generated audio, background noise like that found in radio interference has been persistent. Both Gemini 2.5 Flash Preview and Gemini 2.5 Pro Preview have the same issue going on. I’ve tried everything I can to make those audios better, but whatever tools I try using to correct this issue, the outcome is never satisfactory.
The previous quality was way better.