StepFun launches StepAudio 3, tops two real-time voice benchmarks

StepFun has released StepAudio 3 and rolled out five voice models at once: Realtime, ASR, TTS, Gen, and Music. In two voice evaluations tracked by Artificial Analysis, StepAudio 3 Realtime ranked first in both categories. It scored 98.9% in Conversational Dynamics, ahead of Qwen Audio 3.0 Realtime Plus at 98.4% and GPT-Realtime-2 High at 95.3%. It also posted 99.7% in Speech Reasoning, taking the top spot there as well. According to the benchmark descriptions cited in the source, Conversational Dynamics measures how well a model handles pauses, turn-taking, user interruptions, and short acknowledgements, while Speech Reasoning tests whether a model can directly understand audio and complete reasoning tasks. In ASR, StepAudio 3 recorded a 1.7% WER on Artificial Analysis' non-streaming speech recognition leaderboard, tying for first with Fun-Realtime-ASR-preview. StepAudio 3 Gen also supports one-shot generation of vocals, sound effects, ambient audio, and music, with scene-level arrangement. All five models have now been added to StepFun's voice product lineup.