[ { "voice": [ "brightness/task_comparison/brightness_pair_072.wav" ], "conversations": [ { "from": "human", "value": "You are given two clips with a 0.5-second pause between them. Which has higher perceived brightness? Only answer letter 'A' (refers to the first clip) or 'B' (refers to the second clip). Do not add any explanation, punctuation, or extra text.