The largest performance differences between US and UK English:
➤ Lightning V3.1 Pro: 94 Elo points higher in US English
➤ Qwen-Audio-3.1-TTS-Plus: 66 points higher in US English
➤ Soniox TTS Real-Time v2: 51 points higher in UK English
➤ Speech 2.8 Turbo: 49 points higher in UK English
These differences highlight the importance of evaluating TTS models in the accent relevant to your use case, rather than relying on overall rankings alone.
